Communication terminal, image communication system, display control method, and non-transitory computer-readable medium

ABSTRACT

A communication terminal for displaying a predetermined-area image, which is an image of a part of a whole image, includes circuitry. The circuitry receives first predetermined information specifying a first predetermined area, the first predetermined information being transmitted from another communication terminal displaying a first predetermined-area image, which is an image of the first predetermined-area. The circuitry calculates a position of the first predetermined area with respect to a second predetermined area, based on the first predetermined information received and second predetermined information specifying the second predetermined area, the second predetermined area being an area of a second predetermined-area image being displayed by the communication terminal. The circuitry controls a display to display the second predetermined-area image including at least one of relative position information indicating the position calculated and direction information indicating a direction of the first predetermined area with respect to the second predetermined area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35U.S.C. § 119(a) to Japanese Patent Application Nos. 2017-183742, filedon Sep. 25, 2017 and 2018-177017, filed on Sep. 21, 2018, the entiredisclosures of which are hereby incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a communication terminal, an imagecommunication system, a display control method, and a non-transitorycomputer-readable medium.

Description of the Related Art

Videoconference systems are now in widespread use, allowing users atremote places to hold a remote conference via a communication networksuch as the Internet. In such videoconference systems, a communicationterminal for a videoconference system is provided in a meeting roomwhere attendants of one party in a remote conference are attending. Thiscommunication terminal collects an image or video of the meeting roomincluding the attendants and sound such as speech made by theattendants, and transmits digital data converted from the collectedimage (video) and/or sound to the other party's communication terminalprovided at a different meeting room. Based on the transmitted digitaldata, the other party's communication terminal displays images on adisplay or outputs audio from a speaker in the different meeting room toestablish video calling. This enables to carry out a conference amongremote sites, in a state close to an actual conference.

Additionally, a communication terminal is known that is connected to animage capturing device that can capture a spherical panoramic image inreal time and transmits a spherical panoramic image acquired by theimage capturing device to each communication terminal of the otherparty. The communication terminal of the other party displays, on adisplay, a predetermined-area image representing an image of apredetermined area, which is a part of the spherical panoramic image. Auser in each of remote sites can determine, by his or her own, apredetermined-area image to be displayed, representing an image of apredetermined area that the user is interested in, from a whole image ofthe spherical panoramic image.

SUMMARY

A communication terminal for displaying a predetermined-area image,which is an image of a part of a whole image, includes circuitry. Thecircuitry receives first predetermined information specifying a firstpredetermined area, the first predetermined information beingtransmitted from another communication terminal displaying a firstpredetermined-area image, which is an image of the firstpredetermined-area in the whole image. The circuitry calculates aposition of the first predetermined area with respect to a secondpredetermined area in the whole image, based on the first predeterminedinformation received and second predetermined information specifying thesecond predetermined area, the second predetermined area being an areaof a second predetermined-area image being displayed by thecommunication terminal. The circuitry controls a display to display,based on the position calculated, the second predetermined-area imageincluding at least one of relative position information indicating theposition calculated and direction information indicating a direction ofthe first predetermined area with respect to the second predeterminedarea.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the embodiments and many of theattendant advantages and features thereof can be readily obtained andunderstood from the following detailed description with reference to theaccompanying drawings, wherein:

FIG. 1A is a left side view of an image capturing device according to anembodiment of the present disclosure;

FIG. 1B is a front view of the image capturing device of FIG. 1A;

FIG. 1C is a plan view of the image capturing device of FIG. 1A;

FIG. 2 is an illustration of how a user uses the image capturing deviceaccording to an embodiment of the present disclosure;

FIG. 3A is an illustration of a front side of a hemispherical imagecaptured by the image capturing device according to an embodiment of thepresent disclosure;

FIG. 3B is an illustration of a back side of the hemispherical imagecaptured by the image capturing device according to an embodiment of thepresent disclosure;

FIG. 3C is an illustration of an image captured by the image capturingdevice represented by Mercator projection, according to an embodiment ofthe present disclosure;

FIG. 4A is an illustration of a Mercator image covering a sphere,according to an embodiment of the present disclosure;

FIG. 4B is an illustration of a spherical panoramic image, according toan embodiment of the present disclosure;

FIG. 5 is an illustration of relative positions of a virtual camera anda predetermined area in a case where the spherical panoramic image isrepresented as a three-dimensional solid sphere, according to anembodiment of the present disclosure;

FIG. 6A is a perspective view of FIG. 5;

FIG. 6B is an illustration of an image of the predetermined areadisplayed on a display of a communication terminal, according to anembodiment of the present disclosure;

FIG. 7 is a view illustrating a relation between predetermined-areainformation and a predetermined-area image, according to an embodimentof the present disclosure;

FIG. 8 is a view illustrating points in a three-dimensional Euclideanspace according to spherical coordinates, according to an embodiment ofthe present disclosure;

FIG. 9 is a schematic diagram illustrating a configuration of an imagecommunication system, according to an embodiment of the presentdisclosure;

FIG. 10 is a block diagram illustrating a hardware configuration of theimage capturing device, according to an embodiment of the presentdisclosure;

FIG. 11 is a block diagram illustrating a hardware configuration of avideoconference terminal, according to an embodiment of the presentdisclosure;

FIG. 12 is a block diagram illustrating a hardware configuration of anyone of a communication management system and a personal computer,according to an embodiment of the present disclosure;

FIG. 13 is a block diagram illustrating a hardware configuration of asmartphone, according to an embodiment of the present disclosure;

FIG. 14 is a block diagram illustrating a part of a functionalconfiguration of the image communication system, according to anembodiment of the present disclosure;

FIG. 15 is a block diagram illustrating another part of the functionalconfiguration of the image communication system, according to anembodiment of the present disclosure;

FIG. 16 is a conceptual diagram illustrating an image type managementtable, according to an embodiment of the present disclosure;

FIG. 17 is a conceptual diagram illustrating an image capturing devicemanagement table, according to an embodiment of the present disclosure;

FIG. 18 is a conceptual diagram illustrating a predetermined-areamanagement table, according to an embodiment of the present disclosure;

FIG. 19 is a conceptual diagram illustrating a session management table,according to an embodiment of the present disclosure;

FIG. 20 is a conceptual diagram illustrating an image type managementtable, according to an embodiment of the present disclosure;

FIG. 21 is a conceptual diagram illustrating a predetermined-areamanagement table, according to an embodiment of the present disclosure;

FIG. 22 is a sequence diagram illustrating an operation of participatingin a specific communication session, according to an embodiment of thepresent disclosure;

FIG. 23 is an illustration of a session selection screen for selecting acommunication session (virtual conference room), according to anembodiment of the present disclosure;

FIG. 24 is a sequence diagram illustrating an operation of managingimage type information, according to an embodiment of the presentdisclosure;

FIG. 25A is an illustration of an example state of video calling whenthe image capturing device of FIGS. 1A to 1C is not used, according toan embodiment of the present disclosure;

FIG. 25B is an illustration of an example state of video calling whenthe image capturing device of FIGS. 1A to 1C is used, according to anembodiment of the present disclosure;

FIG. 26 is a sequence diagram illustrating an operation of transmittingcaptured-image data and audio data in a video call, according to anembodiment of the present disclosure;

FIG. 27A is an illustration of an example of a content displayed in onesite, in which image data transmitted from the image capturing device ofFIGS. 1A to 1C is displayed as is, that is, without generating aspherical panoramic image and a predetermined-area image, according toan embodiment of the present disclosure;

FIG. 27B is an illustration of an example of a content displayed in onesite, in which a spherical panoramic image and a predetermined-areaimage are generated based on image data transmitted from the imagecapturing device of FIGS. 1A to 1C, according to an embodiment of thepresent disclosure;

FIG. 27C is an illustration of an example of a content displayed in onesite, in which the predetermined-area image of FIG. 27B is changed,according to an embodiment of the present disclosure;

FIG. 28 is a sequence diagram illustrating an operation of sharing thepredetermined-area information, according to an embodiment of thepresent disclosure;

FIG. 29 is a flowchart illustrating an operation of displaying thepredetermined-area image, according to an embodiment of the presentdisclosure;

FIGS. 30A and 30B are illustrations for explaining how a position of apoint of gaze of another site in a predetermined-area image of own siteis determined, according to an embodiment of the present disclosure;

FIG. 31A is an illustration for explaining definition of angles,according to an embodiment of the present disclosure;

FIG. 31B is an illustration for explaining definitions of angle ranges,according to an embodiment of the present disclosure;

FIGS. 32A to 32C are views, each illustrating a display example of thepredetermined-area image including display direction marks, which isdisplayed in a main display area, according to an embodiment of thepresent disclosure,

FIGS. 33A and 33B are views, each illustrating a display example of thepredetermined-area image including gazing point marks, which isdisplayed in a main display area, according to an embodiment of thepresent disclosure;

FIG. 34 is a view illustrating a display example of thepredetermined-area image including the gazing point mark and the displaydirection marks, which is displayed in a main display area, according toan embodiment of the present disclosure, and

FIG. 35 is a sequence diagram illustrating another operation of sharingthe predetermined-area information, according to an embodiment of thepresent disclosure.

The accompanying drawings are intended to depict embodiments of thepresent disclosure and should not be interpreted to limit the scopethereof. The accompanying drawings are not to be considered as drawn toscale unless explicitly noted.

DETAILED DESCRIPTION

In describing embodiments illustrated in the drawings, specificterminology is employed for the sake of clarity. However, the disclosureof this specification is not intended to be limited to the specificterminology so selected and it is to be understood that each specificelement includes all technical equivalents that have a similar function,operate in a similar manner, and achieve a similar result.

As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the multiple forms as well, unless the context clearly indicatesotherwise.

Hereinafter, a description is given of an embodiment of the presentdisclosure, with reference to drawings.

First Embodiment:

First, referring to FIGS. 1A to 1C to FIG. 34, a first embodiment isdescribed.

<Overview of Embodiment>

<Generation of Spherical Panoramic Image>

Referring to FIGS. 1A to 1C to 7, a description is given of generating aspherical panoramic image.

First, a description is given of an external view of an image capturingdevice 1, with reference to FIGS. 1A to 1C. The image capturing device 1is a digital camera for capturing images from which a three-dimensionalspherical image is generated. In one example, the spherical imagecaptured by the image capturing device 1 is a 360-degree sphericalpanoramic image. FIGS. 1A to 1C are respectively a left side view, afront view, and a plan view of the image capturing device 1.

As illustrated in FIG. 1A, the image capturing device 1 has a shape suchthat one can hold it with one hand. Further, as illustrated in FIGS. 1A,1B, and 1C, an imaging element 103 a is provided on a front side(anterior side) of an upper section of the image capturing device 1, andan imaging element 103 b is provided on a back side (rear side) thereof.These imaging elements (image sensors) 103 a and 103 b are used incombination with optical members (e.g., fisheye lenses 102 a and 102 bof FIG. 10, described below), each being configured to capture ahemispherical image having an angle of view of 180 degrees or wider. Asillustrated in FIG. 1B, the image capturing device 1 further includes anoperation unit 115 such as a shutter button on the rear side of theimage capturing device 1, which is opposite of the front side of theimage capturing device 1.

Next, a description is given of a situation where the image capturingdevice 1 is used, with reference to FIG. 2. FIG. 2 illustrates anexample of how a user uses the image capturing device 1. As illustratedin FIG. 2, for example, the image capturing device 1 is used forcapturing objects surrounding the user who is holding the imagecapturing device 1 in his or her hand. The imaging elements 103 a and103 b illustrated in FIGS. 1A to 1C capture the objects surrounding theuser to obtain two hemispherical images.

Next, a description is given of an overview of an operation ofgenerating a spherical panoramic image from the images captured by theimage capturing device 1, with reference to FIGS. 3A to 3C and FIGS. 4Aand 4B. FIG. 3A is a view illustrating a front side of a hemisphericalimage captured by the image capturing device 1. FIG. 3B is a viewillustrating a back side of a hemispherical image captured by the imagecapturing device 1. FIG. 3C is a view illustrating an image in Mercatorprojection. The image in Mercator projection as illustrated in FIG. 3Cis referred to as a “Mercator image” hereinafter. FIG. 4A is aconceptual diagram illustrating an example of how the Mercator imagemaps to a surface of a sphere. FIG. 4B is a view illustrating aspherical panoramic image.

As illustrated in FIG. 3A, an image captured by the imaging element 103a is a curved hemispherical image (front side) taken through the fisheyelens 102 a described later. Also, as illustrated in FIG. 3B, an imagecaptured by the imaging element 103 b is a curved hemispherical image(back side) taken through the fisheye lens 102 b described later. Thehemispherical image (front side) and the hemispherical image (backside), which is reversed by 180-degree from each other, are combined bythe image capturing device 1. This result in generation of the Mercatorimage as illustrated in FIG. 3C.

The Mercator image is mapped on the sphere surface using Open GraphicsLibrary for Embedded Systems (OpenGL ES) as illustrated in FIG. 4A. Thisresults in generation of the spherical panoramic image as illustrated inFIG. 4B. In other words, the spherical panoramic image is represented asthe Mercator image, which corresponds to a surface facing a center ofthe sphere. It should be noted that OpenGL ES is a graphic library usedfor visualizing two-dimensional (2D) and three-dimensional (3D) data.The spherical panoramic image is either a still image or a moving image.

One may feel strange viewing the spherical panoramic image, because thespherical panoramic image is an image mapped to the sphere surface. Toresolve this strange feeling, an image of a predetermined area, which isa part of the spherical panoramic image, is displayed as a planar imagehaving fewer curves. The image of the predetermined area is referred toas a “predetermined-area image” hereinafter. Hereinafter, a descriptionis given of displaying the predetermined-area image, with reference toFIG. 5 and FIGS. 6A and 6B.

FIG. 5 is a view illustrating positions of a virtual camera IC and apredetermined area T in a case where the spherical image is representedas a surface area of a three-dimensional solid sphere. The virtualcamera IC corresponds to a position of a point of view (viewpoint) of auser who is viewing the spherical image CE represented as a surface areaof the three-dimensional solid sphere CS. FIG. 6A is a perspective viewof the spherical image CE illustrated in FIG. 5. FIG. 6B is a viewillustrating the predetermined-area image Q when displayed on a display.In FIG. 6A, the spherical image CE illustrated in FIG. 4B is representedas a surface area of the three-dimensional solid sphere CS. Assumingthat the spherical image CE is a surface area of the solid sphere CS,the virtual camera IC is outside of the spherical image CE asillustrated in FIG. 5. The predetermined area T in the spherical imageCE is an imaging area of the virtual camera IC. Specifically, thepredetermined area T is specified by predetermined-area informationindicating an imaging direction and an angle of view of the virtualcamera IC in a three-dimensional virtual space containing the sphericalimage CE.

The predetermined-area image Q, which is an image of the predeterminedarea T illustrated in FIG. 6A, is displayed on a display as an image ofan imaging area of the virtual camera IC, as illustrated in FIG. 6B.FIG. 6B illustrates the predetermined-area image Q represented by thepredetermined-area information that is set by default. In anotherexample, the predetermined-area image Q is specified by an imaging area(X, Y, Z) of the virtual camera IC, i.e., the predetermined area T,rather than the predetermined-area information, i.e., the positioncoordinate of the virtual camera IC. The following explains the positionof the virtual camera IC, using an imaging direction (rH, rV) and anangle of view a of the virtual camera IC.

Referring to FIG. 7, a relation between the predetermined-areainformation and an image of the predetermined area T is describedaccording to the embodiment. FIG. 7 is a view illustrating a relationbetween the predetermined-area information and the predetermined area T.As illustrated in FIG. 7, “rH” denotes a horizontal radian, “rV” denotesa vertical radian, and “a” denotes an angle of view, respectively, ofthe virtual camera IC. The position of the virtual camera IC isadjusted, such that the point of gaze of the virtual camera IC,indicated by the imaging direction (rH, rV), matches a center point CPof the predetermined area T as the imaging area of the virtual cameraIC. The predetermined-area image Q is an image of the predetermined areaT, in the spherical image CE. “f” denotes a distance from the virtualcamera IC to the center point CP of the predetermined area T. L is adistance between the center point CP and a given vertex of thepredetermined area T (2L is a diagonal line). In FIG. 7, a trigonometricfunction equation generally expressed by the following equation 1 issatisfied.L/f=tan(α/2)  (Equation 1)

FIG. 8 is a view illustrating points in a three-dimensional Euclideanspace according to spherical coordinates, according to the embodiment. Apositional coordinate (r, θ, φ) is given when the center point CP isrepresented by a spherical polar coordinates system. The positionalcoordinate (r, θ, φ) represents a moving radius, a polar angle, and anazimuth angle. The moving radius r is a distance from an origin of thethree-dimensional virtual space including the spherical panoramic imageto the center point CP. Accordingly, the radius r is equal to f FIG. 8illustrates a relation between these items. The following description isprovided using the positional coordinate (r, θ, φ) of the virtual cameraIC.

<Overview of Image Communication System>

Referring to FIG. 9, an overview of a configuration of an imagecommunication system according to the present embodiment is described.FIG. 9 is a schematic diagram illustrating a configuration of the imagecommunication system according to the present embodiment.

As illustrated in FIG. 9, the image communication system according tothe present embodiment includes an image capturing device 1 a, an imagecapturing device 1 b, a videoconference terminal 3 a, a videoconferenceterminal 3 d, a display 4 a, a display 4 d, a communication managementsystem 5, a personal computer (PC) 7, an image capturing device 8, and asmartphone 9. The videoconference terminal 3 a, the smartphone 9, the PC7, and the videoconference terminal 3 d communicate data with oneanother via a communication network 100 such as the Internet. Thecommunication network 100 can be either a wireless network or a wirednetwork.

Each of the image capturing device 1 a and the image capturing device 1b is a special digital camera, which captures an image of an object orsurroundings such as scenery to obtain two hemispherical images, fromwhich a spherical panoramic image is generated. By contrast, the imagecapturing device 8 is a general-purpose digital camera that captures animage of a subject or surroundings to obtain a general planar image.

Each of the videoconference terminal 3 a and the videoconferenceterminal 3 d is a terminal that is dedicated to videoconferencing. Thevideoconference terminal 3 a and the videoconference terminal 3 ddisplay an image of video calling on the display 4 a and the display 4d, respectively, via a wired cable such as a universal serial bus (USB).The videoconference terminal 3 a usually captures an image by a camera312 of FIG. 11, which is described later. However, in a case where thevideoconference terminal 3 a is connected to a cradle 2 a on which theimage capturing device 1 a is mounted, the image capturing device 1 a ispreferentially used. Accordingly, two hemispherical images are obtained,from which a spherical panoramic image is generated. When a wired cableis used for connecting the videoconference terminal 3 a and the cradle 2a, the cradle 2 a supplies power to the image capturing device 1 a andholds the image capturing device 1 a in addition to establishing acommunication between the image capturing device 1 a and thevideoconference terminal 3 a. In the embodiment, the image capturingdevice 1 a, the cradle 2 a, the videoconference terminal 3 a, and thedisplay 4 a are located in the same site A. In the site A, four usersA1, A2, A3 and A4 are participating in video calling. On the other hand,the videoconference terminal 3 d and the display 4 d are located in thesame site D. In the site D, three users D1, D2, and D3 are participatingin video calling.

The communication management system 5 manages and controls communicationamong the videoconference terminal 3 a, the videoconference terminal 3d, the PC 7 and the smartphone 9. Further, the communication managementsystem 5 manages types (a general image type and a special image type)of image data to be exchanged. Accordingly, the communication managementsystem 5 is a communication control system. In the embodiment, a specialimage is a spherical panoramic image. The communication managementsystem 5 is located, for example, at a service provider that providesvideo communication service. In one example, the communicationmanagement system 5 is configured as a single computer. In anotherexample, the communication management system 5 is constituted as aplurality of computers to which divided portions (functions, means, orstorages) are arbitrarily allocated. In other words, the communicationmanagement system 5 can be implemented by a plurality of servers thatoperate in cooperation with one another.

The PC 7 performs video calling with the image capturing device 8connected thereto. In the embodiment, the PC 7 and the image capturingdevice 8 are located in the same site C. In the site C, one user C isparticipating in video calling.

The smartphone 9 includes a display 917, which is described later, anddisplays an image of video calling on the display 917. The smartphone 9includes a complementary metal oxide semiconductor (CMOS) sensor 905,and usually captures an image with the CMOS sensor 905. In addition, thesmartphone 9 is configured to obtain data of two hemispherical imagescaptured by the image capturing device 1 b, from which a sphericalpanoramic image is generated, using wireless communication such asWireless Fidelity (Wi-Fi) and Bluetooth (registered trademark). Whenwireless communication is used for obtaining the data of twohemispherical images, a cradle 2 b supplies power with the imagecapturing device 1 b and holds the image capturing device 1 b, but notestablish a communication. In the embodiment, the image capturing device1 b, the cradle 2 b, and the smartphone 9 are located in the same siteB. Further, in the site B, two users B1 and B2 are participating invideo calling.

The videoconference terminal 3 a, the videoconference terminal 3 d, thePC 7 and the smartphone 9 are each an example of a communicationterminal. OpenGL ES is installed in each of these communicationterminals to enable each communication terminal to generatepredetermined-area information that indicates a partial area of aspherical panoramic image, or to generate a predetermined-area imagefrom a spherical panoramic image that is transmitted from a differentcommunication terminal.

The arrangement of the terminals (communication terminal, display, imagecapturing device), apparatuses and users illustrated in FIG. 9 is justan example, and any other suitable arrangement will suffice. Forexample, in the site C, an image capturing device configured to capturea spherical panoramic image can be used in place of the image capturingdevice 8. In addition, examples of the communication terminal include adigital television, a smartwatch, and a car navigation device. In thefollowing description, any arbitrary one of the image capturing device 1a and the image capturing device 1 b is referred to as “image capturingdevice 1”. Further, any arbitrary one of the videoconference terminal 3a and the videoconference terminal 3 d is referred to as“videoconference terminal 3”, hereinafter. Furthermore, any arbitraryone of the display 4 a and the display 4 d is referred to as “display4”, hereinafter.

<Hardware Configuration of Embodiment>

Next, referring to FIG. 10 to FIG. 13, a description is given in detailof hardware configurations of the image capturing device 1, thevideoconference terminal 3, the communication management system 5, thePC 7, and the smartphone 9, according to the present embodiment. Sincethe image capturing device 8 is a general-purpose camera, a detaileddescription thereof is omitted.

<Hardware Configuration of Image Capturing Device 1>

First, referring to FIG. 10, a hardware configuration of the imagecapturing device 1 is described according to the embodiment. FIG. 10 isa block diagram illustrating a hardware configuration of the imagecapturing device 1 according to the embodiment. The following describesa case in which the image capturing device 1 is a spherical(omnidirectional) image capturing device having two imaging elements.However, the image capturing device 1 may include any suitable number ofimaging elements, providing that it includes at least two imagingelements. In addition, the image capturing device 1 is not necessarilyan image capturing device dedicated to omnidirectional image capturing.In another example, an external omnidirectional image capturing unit canbe attached to a general-purpose digital camera or a smartphone toimplement an image capturing device having substantially the samefunction as that of the image capturing device 1.

As illustrated in FIG. 10, the image capturing device 1 includes animaging unit 101, an image processing unit 104, an imaging control unit105, a microphone 108, an audio processing unit 109, a centralprocessing unit (CPU) 111, a read only memory (ROM) 112, a static randomaccess memory (SRAM) 113, a dynamic random access memory (DRAM) 114, theoperation unit 115, a network interface (I/F) 116, a communicationdevice 117, and an antenna 117 a.

The imaging unit 101 includes two wide-angle lenses (so-called fisheyelenses) 102 a and 102 b, each having an angle of view of equal to orgreater than 180 degrees so as to form a hemispherical image. Theimaging unit 101 further includes the two imaging elements 103 a and 103b corresponding to the fisheye lenses 102 a and 102 b respectively. Theimaging elements 103 a and 103 b each includes an imaging sensor such asa CMOS sensor and a charge-coupled device (CCD) sensor, a timinggeneration circuit, and a group of registers. The imaging sensorconverts an optical image formed by the fisheye lenses 102 a and 102 binto electric signals to output image data. The timing generationcircuit generates horizontal or vertical synchronization signals, pixelclocks and the like for the imaging sensor. Various commands, parametersand the like for operations of the imaging elements 103 a and 103 b areset in the group of registers.

Each of the imaging elements 103 a and 103 b of the imaging unit 101 isconnected to the image processing unit 104 via a parallel I/F bus. Inaddition, each of the imaging elements 103 a and 103 b of the imagingunit 101 is connected to the imaging control unit 105 via a serial I/Fbus such as an 12C bus. The image processing unit 104 and the imagingcontrol unit 105 are each connected to the CPU 111 via a bus 110.Furthermore, the ROM 112, the SRAM 113, the DRAM 114, the operation unit115, the network OF 116, the communication device 117, and theelectronic compass 118 are also connected to the bus 110.

The image processing unit 104 acquires image data from each of theimaging elements 103 a and 103 b via the parallel I/F bus and performspredetermined processing on each image data. Thereafter, the imageprocessing unit 104 combines these image data to generate data of theMercator image as illustrated in FIG. 3C.

The imaging control unit 105 usually functions as a master device whilethe imaging elements 103 a and 103 b each usually functions as a slavedevice. The imaging control unit 105 sets commands and the like in thegroup of registers of the imaging elements 103 a and 103 b via theserial I/F bus such as the I2C bus. The imaging control unit 105receives necessary commands from the CPU 111. Further, the imagingcontrol unit 105 acquires status data and the like of the group ofregisters of the imaging elements 103 a and 103 b via the serial I/F bussuch as the I2C bus. The imaging control unit 105 sends the acquiredstatus data and the like to the CPU 111.

The imaging control unit 105 instructs the imaging elements 103 a and103 b to output the image data at a time when the shutter button of theoperation unit 115 is pressed. In some cases, the image capturing device1 is configured to display a preview image on a display (e.g., a displayof the videoconference terminal 3 a) or to display a moving image(movie). In case of displaying movie, image data are continuously outputfrom the imaging elements 103 a and 103 b at a predetermined frame rate(frames per minute).

Furthermore, the imaging control unit 105 operates in cooperation withthe CPU 111, to synchronize the time when the imaging element 103 aoutputs image data and the time when the imaging element 103 b outputsthe image data. It should be noted that, although the image capturingdevice 1 does not include a display in the present embodiment, the imagecapturing device 1 can include a display.

The microphone 108 converts sound to audio data (signal). The audioprocessing unit 109 acquires audio data output from the microphone 108via an I/F bus and performs predetermined processing on the audio data.

The CPU 111 controls entire operation of the image capturing device 1and performs necessary processing. The ROM 112 stores various programsfor execution by the CPU 111. The SRAM 113 and the DRAM 114 eachoperates as a work memory to store programs loaded from the ROM 112 forexecution by the CPU 111 or data in current processing. Morespecifically, in one example, the DRAM 114 stores image data currentlyprocessed by the image processing unit 104 and data of the Mercatorimage on which processing has been performed.

The operation unit 115 collectively refers to various operation keys, apower switch, the shutter button, and a touch panel having functions ofboth displaying information and receiving input from a user, which canbe used in combination. A user operates the operation keys to inputvarious image capturing (photographing) modes or image capturing(photographing) conditions.

The network I/F 116 collectively refers to an interface circuit such asa USB I/F that allows the image capturing device 1 to communicate datawith an external medium such as an SD card or an external personalcomputer. The network I/F 116 supports at least one of wired andwireless communications. The data of the Mercator image, which is storedin the DRAM 114, is stored in the external medium via the network I/F116 or transmitted to the external device such as the videoconferenceterminal 3 a via the network I/F 116, at any desired time.

The communication device 117 communicates data with an external devicesuch as the videoconference terminal 3 a via the antenna 117 a of theimage capturing device 1 using a short-range wireless communicationnetwork such as Wi-Fi and Near Field Communication (NFC). Thecommunication device 117 is also configured to transmit the data ofMercator image to the external device such as the videoconferenceterminal 3 a.

The electronic compass 118 calculates an orientation and a tilt (rollangle) of the image capturing device 1 from the Earth's magnetism tooutput orientation and tilt information. This orientation and tiltinformation is an example of related information, which is metadatadescribed in compliance with Exif. This information is used for imageprocessing such as image correction of captured images. The relatedinformation also includes data of a time (date) when an image iscaptured by the image capturing device 1, and data of an amount of imagedata, for example.

<Hardware Configuration of Videoconference Terminal 3>

Next, referring to FIG. 11, a hardware configuration of thevideoconference terminal 3 is described according to the embodiment.FIG. 11 is a block diagram illustrating a hardware configuration of thevideoconference terminal 3 according to the embodiment. As illustratedin FIG. 11, the videoconference terminal 3 includes a CPU 301, a ROM302, a RAM 303, a flash memory 304, a solid state drive (SSD) 305, amedium I/F 307, an operation key 308, a power switch 309, a bus line310, a network I/F 311, a camera 312, an imaging element I/F 313, amicrophone 314, a speaker 315, an audio input/output I/F 316, a displayI/F 317, an external device connection I/F 318, a short-rangecommunication circuit 319, and an antenna 319 a for the short-rangecommunication circuit 319.

The CPU 301 controls entire operation of the videoconference terminal 3.The ROM 302 stores a control program such as an Initial Program Loader(IPL) to boot the CPU 301. The RAM 303 is used as a work area for theCPU 301. The flash memory 304 stores various data such as acommunication control program, image data, and audio data. The SSD 305controls reading or writing of various data to or from the flash memory304 under control of the CPU 301. In alternative to the SSD, a hard discdrive (HDD) can be used. The medium I/F 307 controls reading or writing(storing) of data with respect to a storage medium 306 such as a flashmemory. The operation key (keys) 308 is operated by a user to input auser instruction such as a user selection of a communication destinationof the videoconference terminal 3. The power switch 309 is a switch thatturns on or off the power of the videoconference terminal 3.

The network I/F 311 in an interface that controls communication of datawith an external device through the communication network 100 such asthe Internet. The camera 312 is an example of a built-in imaging deviceconfigured to capture a subject under control of the CPU 301 to obtainimage data. The imaging element I/F 313 is a circuit that controlsdriving of the camera 312. The microphone 314 is an example of abuilt-in audio collecting device configured to input audio. The audioinput/output I/F 316 is a circuit for controlling input and output ofaudio signals between the microphone 314 and the speaker 315 undercontrol of the CPU 301. The display I/F 317 is a circuit fortransmitting image data to the external display 4 under control of theCPU 301. The external device connection I/F 318 is an interface thatconnects the videoconference terminal 3 to various external devices. Theshort-range communication circuit 319 is a communication circuit thatcommunicates in compliance with the NFC (registered trademark), theBluetooth (registered trademark) and the like.

The bus line 310 is an address bus, a data bus or the like, whichelectrically connects the elements in FIG. 11 such as the CPU 301.

The display 4 is an example of display means for displaying an image ofa subject, an operation icon, etc. The display 4 is configured as aliquid crystal display or an organic electroluminescence (EL) display,for example. The display 4 is connected to the display OF 317 by a cable4 c. For example, the cable 4 c is an analog red green blue (RGB) (videographic array (VGA)) signal cable, a component video cable, ahigh-definition multimedia interface (HDMI) (registered trademark)signal cable, or a digital video interactive (DVI) signal cable.

The camera 312 includes a lens and a solid-state imaging element thatconverts an image (video) of a subject to electronic data by convertinglight to electric charge. As the solid-state imaging element, forexample, a CMOS sensor or a CCD sensor is used. The external deviceconnection OF 318 is configured to connect an external device such as anexternal camera, an external microphone, or an external speaker througha USB cable or the like. When an external camera is connected, theexternal camera is driven in preference to the built-in camera 312 undercontrol of the CPU 301. Similarly, when an external microphone isconnected or an external speaker is connected, the external microphoneor the external speaker is driven in preference to the built-inmicrophone 314 or the built-in speaker 315 under control of the CPU 301.

The storage medium 306 is removable from the videoconference terminal 3.In addition to or in alternative to the flash memory 304, any suitablenonvolatile memory, such as an electrically erasable and programmableROM (EEPROM) can be used, provided that it reads or writes data undercontrol of CPU 301.

<Hardware Configuration of Communication Management System 5 and PC 7>

Next, referring to FIG. 12, a hardware configuration of any one of thecommunication management system 5 and the PC 7 is described according tothe embodiment. FIG. 12 is a block diagram illustrating a hardwareconfiguration of any one of the communication management system 5 andthe PC 7 according to the embodiment. In the embodiment, both thecommunication management system 5 and the PC 7 are implemented by acomputer. Therefore, a description is given of a configuration of thecommunication management system 5, and the description of aconfiguration of the PC 7 is omitted, having the same or substantiallythe same configuration as that of the communication management system 5.

The communication management system 5 includes a CPU 501, a ROM 502, aRAM 503, a hard disc (HD) 504, an HDD 505, a media drive 507, a display508, a network OF 509, a keyboard 511, a mouse 512, a compact discrewritable (CD-RW) drive 514, and a bus line 510. The CPU 501 controlsentire operation of the communication management system 5. The ROM 502stores a control program such as an IPL to boot the CPU 501. The RAM 503is used as a work area for the CPU 501. The HD 504 stores various typesof data, such as a control program for the communication managementsystem 5. The HDD 505 controls reading or writing of various data to orfrom the HD 504 under control of the CPU 501. The media drive 507controls reading or writing (storing) of data from and to a storagemedium 506 such as a flash memory. The display 508 displays variousinformation such as a cursor, menu, window, characters, or image. Thenetwork I/F 509 is an interface that controls communication of data withan external device through the communication network 100. The keyboard511 includes a plurality of keys to allow a user to input characters,numerals, or various instructions. The mouse 512 allows a user to selecta specific instruction or execution, select a target for processing, ormove a cursor being displayed. The CD-RW drive 514 controls reading orwriting of various data to and from a CD-RW 513, which is one example ofa removable storage medium. The bus line 510 is an address bus, a databus or the like, which electrically connects the above-describedhardware elements, as illustrated in FIG. 12.

<Hardware Configuration of Smartphone 9>

Referring to FIG. 13, a hardware configuration of the smartphone 9 isdescribed according to the embodiment. FIG. 13 is a block diagramillustrating a hardware configuration of the smartphone 9 according tothe embodiment. As illustrated in FIG. 13, the smartphone 9 includes aCPU 901, a ROM 902, a RAM 903, an EEPROM 904, a CMOS sensor 905, anacceleration and orientation sensor 906, a medium I/F 908, and a globalpositioning system (GPS) receiver 909.

The CPU 901 controls entire operation of the smartphone 9. The ROM 902stores a control program such as an IPL to boot the CPU 901. The RAM 903is used as a work area for the CPU 901. The EEPROM 904 reads or writesvarious data such as a control program for the smartphone 9 undercontrol of the CPU 901. The CMOS sensor 905 captures an object (mainly,a user operating the smartphone 9) under control of the CPU 901 toobtain image data. The acceleration and orientation sensor 906 includesvarious sensors such as an electromagnetic compass for detectinggeomagnetism, a gyrocompass, and an acceleration sensor. The medium I/F908 controls reading or writing of data to and from a storage medium 907such as a flash memory. The GPS receiver 909 receives a GPS signal froma GPS satellite.

The smartphone 9 further includes a long-range communication circuit911, a camera 912, an imaging element I/F 913, a microphone 914, aspeaker 915, an audio input/output I/F 916, a display 917, an externaldevice connection I/F 918, a short-range communication circuit 919, anantenna 919 a for the short-range communication circuit 919, and a touchpanel 921.

The long-range communication circuit 911 is a circuit that communicateswith other device through the communication network 100. The camera 912is an example of a built-in imaging device configured to capture asubject under control of the CPU 901 to obtain image data. The imagingelement OF 913 is a circuit that controls driving of the camera 912. Themicrophone 914 is an example of a built-in audio collecting deviceconfigured to input audio. The audio input/output OF 916 is a circuitfor controlling input and output of audio signals between the microphone914 and the speaker 915 under control of the CPU 901. The display 917 isan example of a display device that displays an image of a subject,various icons, etc. The display 917 is configured as a liquid crystaldisplay or an organic EL display, for example. The external deviceconnection OF 918 is an interface that connects the smartphone 9 tovarious external devices. The short-range communication circuit 919 is acommunication circuit that communicates in compliance with the NFC, theBluetooth and the like. The touch panel 921 is an example of an inputdevice that enables a user to operate the smartphone 9 by touching ascreen of the display 917.

The smartphone 9 further includes a bus line 910. The bus line 910 is anaddress bus, a data bus or the like, which electrically connects theelements in FIG. 13 such as the CPU 901.

It should be noted that a storage medium such as a CD-ROM storing any ofthe above-described programs and/or an HD storing any of theabove-described programs can be distributed domestically or overseas asa program product.

<Functional Configuration of Embodiment>

Referring to FIGS. 14 to 20, a functional configuration of the imagecommunication system is described according to the present embodiment.FIG. 14 and FIG. 15 are block diagrams, each illustrating a part of afunctional configuration of the image communication system.

<Functional Configuration of Image Capturing Device 1 a>

As illustrated in FIG. 14, the image capturing device 1 a includes anacceptance unit 12 a, an image capturing unit 13 a, an audio collectingunit 14 a, a communication unit 18 a, and a data storage/read unit 19 a.Each of the above-mentioned units is a function or means that isimplemented by or that is caused to function by operating any one ormore of the hardware elements illustrated in FIG. 10 in cooperation withinstructions from the CPU 111 according to a control program for theimage capturing device 1 a, expanded from the SRAM 113 to the DRAM 114.

The image capturing device 1 a further includes a memory 1000 a, whichis implemented by the ROM 112, the SRAM 113, and the DRAM 114illustrated in FIG. 10. The memory 1000 a stores therein a globallyunique identifier (GUID) identifying the own device (i.e., the imagecapturing device 1 a itself).

The image capturing device 1 b includes an acceptance unit 12 b, animage capturing unit 13 b, an audio collecting unit 14 b, acommunication unit 18 b, a data storage/read unit 19 b, and a memory1000 b. These functional units of the image capturing device 1 bimplement the similar or substantially the similar functions as those ofthe acceptance unit 12 a, the image capturing unit 13 a, the audiocollecting unit 14 a, the communication unit 18 a, the data storage/readunit 19 a, and the memory 1000 a of the image capturing device 1 a,respectively. Therefore, redundant descriptions thereof are omittedbelow.

(Each Functional Unit of Image Capturing Device 1 a)

Referring to FIG. 10 and FIG. 14, each of the functional units of theimage capturing device 1 a is described in detail.

The acceptance unit 12 a of the image capturing device 1 a is mainlyimplemented by the operation unit 115 illustrated in FIG. 10, whichoperates under control of the CPU 111. The acceptance unit 12 a receivesan instruction input from the operation unit 115 according to a useroperation.

The image capturing unit 13 a is implemented mainly by the imaging unit101, the image processing unit 104, and the imaging control unit 105,illustrated in FIG. 10, each of which operates under control of the CPU111. The image capturing unit 13 a captures an image of an object orsurroundings to obtain captured-image data.

The audio collecting unit 14 a is mainly implemented by the microphone108 and the audio processing unit 109 illustrated in FIG. 10, each ofwhich operates under control of the CPU 111. The audio collecting unit14 a collects sounds around the image capturing device 1 a.

The communication unit 18 a, which is mainly implemented by instructionsof the CPU 111, communicates data with a communication unit 38 a of thevideoconference terminal 3 a using a short-range wireless communicationnetwork in compliance with NFC, Bluetooth, or Wi-Fi, for example.

The data storage/read unit 19 a, which is mainly implemented byinstructions of the CPU 111 illustrated in FIG. 10, stores various dataor information in the memory 1000 a or reads out various data orinformation from the memory 1000 a.

<Functional Configuration of Videoconference Terminal 3 a>

As illustrated in FIG. 14, the videoconference terminal 3 a includes adata exchange unit 31 a, an acceptance unit 32 a, an image and audioprocessor 33 a, a display control unit 34 a, a determination unit 35 a,a generator 36 a, a calculation unit 37 a, communication unit 38 a, anda data storage/read unit 39 a. Each of the above-mentioned units is afunction or means that is implemented by or that is caused to functionby operating any one or more of the hardware elements illustrated inFIG. 11 in cooperation with instructions from the CPU 301 according to acontrol program for the videoconference terminal 3 a, expanded from theflash memory 304 to the RAM 303.

The videoconference terminal 3 a further includes a memory 3000 a, whichis implemented by the ROM 302, the RAM 303, and the flash memory 304illustrated in FIG. 11. The memory 3000 a includes an image typemanagement DB 3001 a, an image capturing device management DB 3002 a,and a predetermined-area management DB 3003 a. Among these DBs, theimage type management DB 3001 a is implemented by an image typemanagement table as illustrated in FIG. 16. The image capturing devicemanagement DB 3002 a is implemented by an image capturing devicemanagement table as illustrated in FIG. 17. The predetermined-areamanagement DB 3003 a is implemented by a predetermined-area managementtable as illustrated in FIG. 18.

The videoconference terminal 3 d includes a data exchange unit 31 d, anacceptance unit 32 d, an image and audio processor 33 d, a displaycontrol unit 34 d, a determination unit 35 d, a generator 36 d, acalculation unit 37 d, a communication unit 38 d, and a datastorage/read unit 39 d, and a memory 3000 d. These functional units ofthe videoconference terminal 3 d implement the similar of substantiallythe similar functions as those of the data exchange unit 31 a, theacceptance unit 32 a, the image and audio processor 33 a, the displaycontrol unit 34 a, the determination unit 35 a, the generator 36 a, thecalculation unit 37 a, the communication unit 38 a, the datastorage/read unit 39 a, and the memory 3000 a of the videoconferenceterminal 3 a. Therefore, redundant descriptions thereof are omittedbelow. In addition, the memory 3000 d of the videoconference terminal 3d includes an image type management DB 3001 d, and an image capturingdevice management DB 3002 d, and a predetermined-area management DB 3003d. These DBs 3001 d, 3002 d and 3003 d have the same or thesubstantially the same data structure as the image type management DB3001 a, the image capturing device management DB 3002 a, and thepredetermined-area management DB 3003 a of the videoconference terminal3 a, respectively. Therefore, redundant descriptions thereof are omittedbelow.

(Image Type Management Table)

FIG. 16 is an illustration of an example data structure of the imagetype management table. The image type management table stores an imagedata identifier (ID), an internet protocol (IP) address, which is anexample of an address of a terminal as a transmission source of imagedata, and a source name, in association with one another. The terminalas a transmission source is hereinafter referred to as a “senderterminal”. The image data ID is one example of image data identificationinformation identifying image data to be used in video communication. Anidentical image data ID is assigned to image data transmitted from thesame sender terminal. Accordingly, a destination terminal (that is, acommunication terminal that receives image data) identifies a senderterminal from which the received image data is transmitted. An IPaddress of the sender terminal, which is associated with specific imagedata ID, is an IP address of a communication terminal that transmitsimage data identified by that image data ID associated with the IPaddress. A source name, which is associated with specific image data ID,is a name for specifying an image capturing device that outputs theimage data identified by that image data ID associated with the sourcename. The source name is one example of image type information. Thesource name is a name generated by a communication terminal such as thevideoconference terminal 3 a according to a predetermined naming rule.

The example of the image type management table illustrated in FIG. 16indicates that four communication terminals, whose IP addresses arerespectively “1.2.1.3”, “1.2.2.3”, “1.3.1.3”, and “1.3.2.3” transmitimage data identified by the image data ID “RS001”, “RS002”, “RS003”,and “RS004”, respectively. Further, according to the image typemanagement table illustrated in FIG. 16, the image types represented bythe source names of those four communication terminals are“Video_Theta”, “Video_Theta”, “Video”, and “Video” that indicated theimage types, which are “special image”, “special image”, “generalimage”, and “general image”, respectively. In the embodiment, the“special image” is a spherical panoramic image.

In another example, data other than the image data are stored in theimage type management table in association with the image data ID.Examples of the data other than the image data include audio data andpresentation material data to be shared on a screen. In addition, dataother than the image data may be stored in the image type managementtable in association with the image data ID. Examples of the data otherthan the image data include audio data and presentation material data tobe shared on a screen.

(Image Capturing Device Management Table)

FIG. 17 is an illustration of an example data structure of the imagecapturing device management table. The image capturing device managementtable stores a vendor ID and a product ID among the GUID of an imagecapturing device that is configured to obtain two hemispherical images,from which a spherical panoramic image is generated. As the GUID, acombination of a vendor ID (VID) and a product ID (PID) used in a USBdevice is used, for example. The vendor ID and the product ID are storedin a communication terminal such as a videoconference terminal beforeshipment. In another example, these IDs are added and stored in thevideoconference terminal after shipment.

(Predetermined-Area Management Table)

FIG. 18 is an illustration of an example data structure of thepredetermined-area management table. The predetermined-area managementtable stores an IP address of a communication terminal (sender terminal)as a transmission source of captured-image data representing a capturedimage, an IP address of a communication terminal (destination terminal)as a destination of the captured-image data, and predetermined-areainformation indicating a predetermined-area image being displayed at thedestination terminal, in association with one another. The destinationterminal of the captured-image data is identical with the senderterminal of the predetermined-area information. The predetermined-areainformation is a conversion parameter used to convert from a capturedimage to an image (predetermined-area image) of a predetermined area Tof the captured image, as illustrated in FIG. 6A, FIG. 6B, and FIG. 7.The IP address is used as one example of address information. Otherexamples of the address information include a media access control (MAC)address and a terminal ID, which identifies a correspondingcommunication terminal. In the embodiment, an IPv4 address is simplifiedto represent the IP address. In another example, an IPv6 address is usedas the IP address.

In the example of FIG. 18, the predetermined-area management tableindicates, in the first line to the third line of the table, that thevideoconference terminal 3 a having an IP address of “1.2.1.3” transmitscaptured-image data, via the communication management system 5, to thevideoconference terminal 3 d having an IP address of “1.2.2.3”, the PC 7having an IP address of “1.3.1.3”, and the smartphone 9 having an IPaddress of “1.3.2.3”. Further, the predetermined-area management tableillustrated in FIG. 18 indicates that the videoconference terminal 3 dis a sender terminal of the predetermined-area information (r=10, θ=20,φ=30). In substantially the same manner, the predetermined-areamanagement table indicates that the PC 7 is a sender terminal of thepredetermined-area information (r=20, θ=30, φ=40). Furthermore, thepredetermined-area management table indicates that the smartphone 9 is asender terminal of the predetermined-area information (r=30, θ=40,φ=50).

When the data exchange unit 31 a newly receives predetermined-areainformation including the same set of IP addresses of the senderterminal of captured-image data and the destination terminal ofcaptured-image data as that currently managed in the table, the datastorage/read unit 39 a overwrites currently managed predetermined-areainformation with the newly received predetermined-area information.

(Each Functional Unit of Videoconference Terminal 3 a)

Referring to FIG. 11 and FIG. 14, each of the functional units of thevideoconference terminal 3 a is described in detail.

The data exchange unit 31 a of the videoconference terminal 3 a ismainly implemented by the network I/F 311 illustrated in FIG. 11, whichoperates under control of the CPU 301. The data exchange unit 31 aexchanges various data or information with communication managementsystem 5 via the communication network 100.

The acceptance unit 32 a is mainly implemented by the operation key 308,which operates under control of the CPU 301. The acceptance unit 32 areceives selections or inputs according to a user operation. In anotherexample, an input device such as a touch panel is used in alternative toor in place of the operation key 308.

The image and audio processor 33 a, which is implemented by instructionsof the CPU 301 illustrated in FIG. 11, processes image data obtained bycapturing a subject by the camera 312. After voice sound generated by auser is converted to audio signals by the microphone 314, the image andaudio processor 33 a performs processing on audio data based on theaudio signals.

Further, the image and audio processor 33 a processes image datareceived from another communication terminal based on the image typeinformation such as the source name, to enable the display control unit34 a to control the display 4 to display an image based on the processedimage data. More specifically, when the image type information indicates“special image”, the image and audio processor 33 a converts the imagedata such as hemispherical image data as illustrated in FIGS. 3A and 3Binto spherical image data to generate spherical panoramic image data asillustrated in FIG. 4B, and further generates a predetermined-area imageas illustrated in FIG. 6B. Furthermore, the image and audio processor 33a outputs, to the speaker 315, audio signals according to audio datareceived from another communication terminal via the communicationmanagement system 5. The speaker 315 outputs sound based on the audiosignal.

The display control unit 34 a is mainly implemented by the display I/F317, which operates under control of the CPU 301. The display controlunit 34 a controls the display 4 to display various images orcharacters.

The determination unit 35 a, which is mainly implemented by instructionsof the CPU 301, determines an image type according to image datareceived from, for example, the image capturing device 1 a.

The generator 36 a is mainly implemented by instructions of the CPU 301.The generator 36 a generates a source name, which is one example of theimage type information, according to the above-described naming rule,based on a determination result obtained by the determination unit 35 aindicating one of a general image or a special image (the “specialimage” is a spherical panoramic image in the embodiment). For example,when the determination unit 35 a determines that the image type is ageneral image, the generator 36 a generates a source name “Video”indicating a general image type. By contrast, when the determinationunit 35 a determines that the image type is a special image, thegenerator 36 a generates a source name “Video_Theta” indicating aspecial image type.

The calculation unit 37 a is mainly implemented by instructions of theCPU 301. The calculation unit 37 a calculates a position (positioninformation) of a predetermined area T1 with respect to a predeterminedarea T2 in the captured image based on predetermined-area information(i2) that is information on the predetermined area T2 andpredetermined-area information (i1) that is received from anothercommunication terminal by the data exchange unit 31 a. Thepredetermined-area information (i1) indicates the predetermined area T1in the captured image. In the embodiment, an image displayed when thecaptured image is entirely displayed may be referred to as a “wholeimage”.

The communication unit 38 a is mainly implemented by the short-rangecommunication circuit 319 and the antenna 319 a, each of which operatesunder control of the CPU 301. The communication unit 38 a communicatesdata with the communication unit 18 a of the image capturing device 1 ausing a short-range wireless communication network in compliance withNFC, Bluetooth, or Wi-Fi, for example. In the above description, thecommunication unit 38 a and the data exchange unit 31 a individuallyhave a communication unit. In another example, the communication unit 38a and the data exchange unit 31 a share a single communication unit.

The data storage/read unit 39 a, which is mainly implemented byinstructions of the CPU 301 illustrated in FIG. 11, stores various dataor information in the memory 3000 or reads out various data orinformation from the memory 3000.

<Functional Configuration of Communication Management System 5>

Referring to FIG. 12 and FIG. 15, each of the functional units of thecommunication management system 5 is described in detail. Thecommunication management system 5 includes a data exchange unit 51, adetermination unit 55, a generator 56, and a data storage/read unit 59.Each of the above-mentioned units is a function or means that isimplemented by or that is caused to function by operating any one ormore of the hardware elements illustrated in FIG. 12 in cooperation withinstructions from the CPU 501 according to a control program for thecommunication management system 5, expanded from the HD 504 to the RAM503.

The communication management system 5 further includes a memory 5000,which is implemented by the RAM 503 and the RD 504 illustrated in FIG.12. The memory 5000 includes a session management DB 5001, an image typemanagement DB 5002, and a predetermined-area management DB 5003. Thesession management DB 5001 is implemented by a session management tableillustrated in FIG. 19. The image type management DB 5002 is implementedby an image type management table illustrated in FIG. 20. Thepredetermined-area management DB 5003 is implemented by apredetermined-area management table illustrated in FIG. 21.

(Session Management Table)

FIG. 19 is an illustration of an example data structure of the sessionmanagement table. The session management table stores a session ID andan IP address of a participant communication terminal, in associationwith each other. The session ID is one example of session identificationinformation for identifying a session that implements video calling. Thesession ID is generated for each virtual conference room. The session IDis also stored in each communication terminal such as thevideoconference terminal 3 a. Each communication terminal selects adesired session ID from the session ID or IDs stored therein. The IPaddress of the participant communication terminal indicates an IPaddress of the communication terminal participating in a virtualconference room identified by the associated session ID.

(Image Type Management Table)

FIG. 20 is an illustration of an example data structure of the imagetype management table. The image type management table illustrated inFIG. 20 stores, in addition to the information items stored in the imagetype management table illustrated in FIG. 16, the same session IDs asthose stored in the session management table, in association with oneanother. The example of the image type management table illustrated inFIG. 20 indicates that three communication terminals whose IP addressesare “1.2.1.3”, “1.2.2.3”, and “1.3.1.3” are participating in the virtualconference room identified by the session ID “se101”. The communicationmanagement system 5 stores the same image data ID, IP address of thesender terminal, and image type information as those stored in acommunication terminal, such as the videoconference terminal 3 a. Thisenables the communication management system 5 to transmit the image typeinformation, etc., to a communication terminal that is currentlyparticipating in a video call and another communication terminal thatnewly participates in the video call by entering a virtual conferenceroom of the video communication. Accordingly, the communication terminalthat is already in the video calling and the communication terminal thatis newly participates in the video calling do not have to exchange suchinformation as the image type information with each other.

(Predetermined-Area Management Table)

FIG. 21 is an illustration of an example data structure of thepredetermined-area management table. The predetermined-area managementillustrated in FIG. 21 has substantially the same data structure as thepredetermined-area management table illustrated in FIG. 18. However, asdescribed later, since the data exchange unit 51 transmits, to eachcommunication terminal, the latest predetermined-area information atregular intervals such as every thirty seconds, all thepredetermined-area information received by the data exchange unit 51during a period from when the predetermined-area information istransmitted last time to when the most recent predetermined-areainformation is transmitted, is kept stored without being deleted. In theexample of FIG. 21, the more recent the predetermined-area informationis, the upper row in the predetermined-area management table.

(Each Functional Unit of Communication Management System 5)

Referring to FIG. 12 and FIG. 15, each of the functional units of thecommunication management system 5 is described in detail.

The data exchange unit 51 of the communication management system 5 ismainly implemented by the network I/F 509, which operates under controlof the CPU 501 illustrated in FIG. 12. The data exchange unit 51exchanges various data or information with the videoconference terminal3 a, the videoconference terminal 3 d, or the PC 7 through thecommunication network 100.

The determination unit 55, which is mainly implemented by instructionsof the CPU 501, performs various determinations.

The generator 56, which is mainly implemented by instructions of the CPU501, generates an image data ID.

The data storage/read unit 59 is mainly implemented by the HDD 505illustrated in FIG. 12, when operates under control of the CPU 501. Thedata storage/read unit 59 stores various data or information in thememory 5000 or reads out various data or information from the memory5000.

<Functional Configuration of PC 7>

Referring to FIGS. 12 and 15, a functional configuration of the PC 7 isdescribed according to the embodiment. The PC 7 has substantially thesame functions as those of the videoconference terminal 3 a. In otherwords, as illustrated in FIG. 15, the PC 7 includes a data exchange unit71, an acceptance unit 72, an image and audio processor 73, a displaycontrol unit 74, a determination unit 75, a generator 76, a calculationunit 77, a communication unit 78, and a data storage/read unit 79. Eachof the above-mentioned units is a function or means that is implementedby or that is caused to function by operating any one or more of thehardware elements illustrated in FIG. 12 in cooperation withinstructions from the CPU 501 according to a control program for the PC7, expanded from the HD 504 to the RAM 503.

The PC 7 further includes a memory 7000, which is implemented by the ROM502, the RAM 503 and the HD 504 illustrated in FIG. 12. The memory 7000includes an image type management DB 7001, an image capturing devicemanagement DB 7002, and a predetermined-area management DB 7003. Theimage type management DB 7001, the image capturing device management DB7002, and the predetermined-area management DB 7003 have substantiallythe same data structure as the image type management DB 3001 a, theimage capturing device management DB 3002 a, and the predetermined-areamanagement DB 3003 a, respectively, and redundant descriptions thereofare omitted below.

(Each Functional Unit of PC 7)

The data exchange unit 71 of the PC 7 is mainly implemented by thenetwork I/F 509, which operates under control of the CPU 501 illustratedin FIG. 12. The data exchange unit 71 implements the similar orsubstantially the similar function to that of the data exchange unit 31a.

The acceptance unit 72 is mainly implemented by the keyboard 511 and themouse 512, which operates under control of the CPU 501. The acceptanceunit 72 implements the similar or substantially the similar function tothat of the acceptance unit 32 a. The image and audio processor 73,which is mainly implemented by instructions of the CPU 501, implementsthe similar or substantially the similar function to that of the imageand audio processor 33 a. The display control unit 74, which is mainlyimplemented by instructions of the CPU 501, implements the similar orsubstantially the similar function to that of the display control unit34 a. The determination unit 75, which is mainly implemented byinstructions of the CPU 501, implements the similar or substantially thesimilar function to that of the determination unit 35 a. The generator76, which is mainly implemented by instructions of the CPU 501,implements the similar or substantially the similar function to that ofthe generator 36 a. The calculation unit 77, which is mainly implementedby instructions of the CPU 501, implements the similar or substantiallythe similar function to that of the calculation unit 37 a. Thecommunication unit 78, which is mainly implemented by instructions ofthe CPU 501, implements the similar or substantially the similarfunction to that of the communication unit 38 a. The data storage/readunit 79, which is mainly implemented by instructions of the CPU 501,stores various data or information in the memory 7000 or reads outvarious data or information from the memory 7000.

<Functional Configuration of Smartphone 9>

Referring to FIG. 13 and FIG. 14, a functional configuration of thesmartphone 9 is described according to the embodiment. The smartphone 9has substantially the same functions as the videoconference terminal 3a. In other words, as illustrated in FIG. 14, the smartphone 9 includesa data exchange unit 91, an acceptance unit 92, an image and audioprocessor 93, a display control unit 94, a determination unit 95, agenerator 96, a calculation unit 97, a communication unit 98, and a datastorage/read unit 99. Each of the above-mentioned units is a function ormeans that is implemented by or that is caused to function by operatingany one or more of the hardware elements illustrated in FIG. 13 incooperation with instructions from the CPU 901 according to a controlprogram for the smartphone 9, expanded from the EEPROM 904 to the RAM903.

The smartphone 9 further includes a memory 9000, which is implemented bythe ROM 902, the RANI 903, and the EEPROM 904 illustrated in FIG. 13.The memory 9000 includes an image type management DB 9001, an imagecapturing device management DB 9002, and a predetermined-area managementDB 9003. The image type management DB 9001, the image capturing devicemanagement DB 9002, and the predetermined-area management DB 9003 havesubstantially the same data structure as the image type management DB3001 a, the image capturing device management DB 3002 a, and thepredetermined-area management DB 3003 a, respectively, and redundantdescriptions thereof are omitted below.

(Each Functional Unit of Smartphone 9)

The data exchange unit 91 of the smartphone 9 is mainly implemented bythe long-range communication circuit 911 illustrated in the FIG. 13,which operates under control of the CPU 901. The data exchange unit 91implements the similar or substantially the similar function to that ofthe data exchange unit 31 a.

The acceptance unit 92 is mainly implemented by the touch panel 921,which operates under control of the CPU 901. The acceptance unit 92implements the similar or substantially the similar function to that ofthe acceptance unit 32 a.

The image and audio processor 93, which is mainly implemented byinstructions of the CPU 901, implements the similar or substantially thesimilar function to that of the image and audio processor 33 a. Thedisplay control unit 94, which is mainly implemented by instructions ofthe CPU 901, implements the similar or substantially the similarfunction to that of the display control unit 34 a. The determinationunit 95, which is mainly implemented by instructions of the CPU 901,implements the similar or substantially the similar function to that ofthe determination unit 35 a. The generator 96, which is mainlyimplemented by instructions of the CPU 901, implements the similar orsubstantially the similar function to that of the generator 36 a. Thecalculation unit 97, which is mainly implemented by instructions of theCPU 901, implements the similar or substantially the similar function tothat of the calculation unit 37 a. The communication unit 98, which ismainly implemented by instructions of the CPU 901, implements thesimilar or substantially the similar function to that of thecommunication unit 38 a. The data storage/read unit 99, which isimplemented by instructions of the CPU 901, stores various data orinformation in the memory 9000 or reads out various data or informationfrom the memory 9000.

<Operation or Processes of Embodiment>

Referring to FIGS. 22 to 34, a description is given of an operation orprocesses according to the present embodiment.

<Participation Process>

Referring to FIG. 22 and FIG. 23, a participation process ofparticipating in a specific communication session is described accordingto the embodiment. FIG. 22 is a sequence diagram illustrating aparticipation process of participating in a specific communicationsession according to the embodiment. FIG. 23 is an illustration of asession selection screen for selecting a communication session (virtualconference room) according to the embodiment.

When a user in the site A (e.g., user A1) operates the videoconferenceterminal 3 a to display the session selection screen for selecting adesired communication session (virtual conference room), the acceptanceunit 32 a receives the operation to display the session selectionscreen. Accordingly, the display control unit 34 a controls the display4 a to display the session selection screen as illustrated in FIG. 23(step S21). In the session selection screen, selection buttons b1, b2,and b3 are displayed. The selection buttons b1, b2, and b3 respectivelyindicates virtual conference rooms R1, R2, R3, each of which is aselection target. Each of the selection buttons b1, b2, and b3 isassociated with a corresponding session ID.

When the user A1 selects a desired selection button (in this example,the selection button b1) on the session selection screen, the acceptanceunit 32 a accepts selection of a corresponding communication session(step S22). Then, the data exchange unit 31 a transmits a request toparticipate in the communication session, namely to enter thecorresponding virtual conference room, to the communication managementsystem 5 (step S23). This participation request includes the session IDidentifying the communication session for which the selection isaccepted at S22, and the IP address of the videoconference terminal 3 a,which is a request sender terminal. The communication management system5 receives the participation request at the data exchange unit 51.

Next, the data storage/read unit 99 performs a process for enabling thevideoconference terminal 3 a to participate in the communication session(step S24). More specifically, the data storage/read unit 99 adds, inthe session management DB 5001 (FIG. 19), the IP address that isreceived at S23 to a field of the participant terminal IP address in arecord of the session ID that is the same as the session ID received atS23. The data exchange unit 51 transmits a response to the participationrequest to the videoconference terminal 3 a (step S25). This response tothe participation request includes the session ID that is received atS23, and a result of the participation process. The videoconferenceterminal 3 a receives the response to the participation request at thedata exchange unit 31 a. The following describes a case where theprocess for enabling the videoconference terminal 3 a to participate inthe communication session, namely the participation process, issuccessfully completed.

<Process of Managing Image Type Information>

Next, referring to FIG. 24, a management process of the image typeinformation is described according to the embodiment. FIG. 24 is asequence diagram illustrating a management process of the image typeinformation according to the embodiment.

When a user (e.g., the user A1) in the site A connects the cradle 2 a,on which the image capturing device 1 a is mounted, to thevideoconference terminal 3 a, using a wired cable such as a USB cable,the data storage/read unit 19 a of the image capturing device 1 a readsout the GUID of the own device (e.g., the image capturing device 1 a)from the memory 1000 a. Then, the communication unit 18 a transmits theown device's GUID to the communication unit 38 a of the videoconferenceterminal 3 a (step S51). The videoconference terminal 3 a receives theGUID of the image capturing device 1 a at the communication unit 38 a.

Subsequently, the determination unit 35 a of the videoconferenceterminal 3 a determines whether a vendor ID and a product ID same as theGUID received at S51 are stored in the image capturing device managementDB 3002 a (see FIG. 17) to determine the image type (step S52). Morespecifically, the determination unit 35 a determines that the imagecapturing device 1 a is an image capturing device that captures aspecial image (a spherical panoramic image, in the embodiment), based ondetermination that the same vender ID and product ID are stored in theimage capturing device management DB 3002 a. By contrast, thedetermination unit 35 a determines that the image capturing device 1 ais an image capturing device that captures a general image, based ondetermination that the same vender ID and product ID are not stored inthe image capturing device management DB 3002 a.

Next, the data storage/read unit 39 a stores, in the image typemanagement DB 3001 a (FIG. 16), the IP address of the own terminal(i.e., videoconference terminal 3 a), which is a sender terminal, inassociation with the image type information, which is a determinationresult determined at S52 (step S53). In this state, the image data ID isnot yet associated. Examples of the image type information include asource name, which is determined according to the naming rule, and animage type (general image or special image).

Then, the data exchange unit 31 a transmits a request for addition ofthe image type information to the communication management system 5(step S54). This request for addition of image type information includesthe IP address of the own terminal as a sender terminal, and the imagetype information, both being stored at S53 in association with eachother. The communication management system 5 receives the request foraddition of the image type information at the data exchange unit 51.

Next, the data storage/read unit 59 of the communication managementsystem 5 searches the session management DB 5001 (FIG. 19) using the IPaddress of the sender terminal received at S54 as a search key, to readout the session ID associated with the IP address (step S55).

Next, the generator 56 generates a unique image data ID (step S56).Then, the data storage/read unit 59 stores, in the image type managementDB 5002 (FIG. 20), a new record associating the session ID that is readout at S55, the image data ID generated at S56, the IP address of thesender terminal and the image type information that are received at S54,with one another (step S57). The data exchange unit 51 transmits theimage data ID generated at S56 to the videoconference terminal 3 a. Thevideoconference terminal 3 a receives the image data ID at the dataexchange unit 31 a (step S58).

Next, the data storage/read unit 39 a of the videoconference terminal 3a stores, in the image type management DB 3001 a (see FIG. 16), theimage data ID received at S58, in association with the IP address of theown terminal (i.e., videoconference terminal 3 a) as the sender terminaland the image type information that are stored at S53 (step S59).

Further, the data exchange unit 51 of the communication managementsystem 5 transmits a notification of addition of the image typeinformation to another communication terminal (videoconference terminal3 d in the embodiment) (step S60). This notification of addition of theimage type information includes the image data ID generated at S56, andthe IP address of the own terminal (i.e., videoconference terminal 3 a)as the sender terminal and the image type information that are stored atS53. The videoconference terminal 3 d receives the notification ofaddition of the image type information at the data exchange unit 31 d.The destination of the notification transmitted by the data exchangeunit 51 is indicated by an IP address associated with the session IDwith which the IP address of the videoconference terminal 3 a isassociated in the session management DB 5001 (see FIG. 19). In otherwords, the destination includes other communication terminal(s) that is(are) in the same virtual conference room where the videoconferenceterminal 3 a is participating.

Next, the data storage/read unit 39 d of the videoconference terminal 3d stores, in the image type management DB 3001 d (see FIG. 16), a newrecord associating the image data ID, the IP address of the senderterminal, and the image type information, which are received at S60(step S61). In substantially the same manner, the notification ofaddition of the image type information is transmitted to the smartphone9 and the PC 7, which are other communication terminal, and then thesmartphone 9 and the PC 7 stores the image type information, etc. in theimage type management DB 9001 and the image type management DB 7001,respectively. Through the process as described above, the sameinformation is shared among the communication terminals by being storedin the image type management DB 3001 a, the image type management DB3001d, the image type management DB 7001 and the image type management DB9001.

<Communication Process of Captured-Image Data>

Next, referring to FIGS. 25 to 34, a process of communicatingcaptured-image data in video calling is described according to theembodiment. FIGS. 25A and 25B illustrate example states of videocalling. More specifically, FIG. 25A illustrates a case where the imagecapturing device 1 a is not used, while FIG. 25B illustrates a casewhere the image capturing device 1 a is used.

As illustrated in FIG. 25A, when the camera 312 (see FIG. 11), which isbuilt into the videoconference terminal 3 a, is used and the imagecapturing device 1 a is not used, the videoconference terminal 3 a hasto be placed in a corner of a table, so that images of the users A1 toA4 can be captured by the camera 312 having a field angle that ishorizontally 125 degrees and vertically 70 degrees. This requires theusers A1 to A4 to talk while looking in the direction of thevideoconference terminal 3 a. Because the user A1 to A4 look in thedirection of the videoconference terminal 3 a, the display 4 a also hasto be placed on the same side as the videoconference terminal 3 a. Thisrequires the user A2 and the user A4, who are away from thevideoconference terminal 3 a, to talk in a relatively loud voice,because they are away from the microphone 314 (see FIG. 11) built in thevideoconference terminal 3 a. Further, the user A2 and A4 havedifficulty in viewing contents displayed on the display 4 a.

By contrast, as illustrated in FIG. 25B, when the image capturing device1 a is used, the videoconference terminal 3 a and the display 4 a areallowed to be placed relatively in the center of the desk, because theimage capturing device 1 a is configured to obtain two hemisphericalimages, from which a spherical panoramic image is generated. Comparingwith the case where the image capturing device 1 a is not used asillustrated in FIG. 25A, the users A1 to A4 can talk with a relativelysmall volume, because they are closer to the microphone 314. Further, itgets easier for the users A1 to A4 to view contents displayed on thedisplay 4 a. In addition, in the right side of the site A, a whiteboard6 is provided, on which the users A1 to A4 can write characters orimages.

Referring to FIG. 26, a description is given of a process oftransmitting captured-image data and audio data obtained in the site Aillustrated in FIG. 25B to other communication terminals (smartphone 9,PC 7, and videoconference terminal 3 d) via the communication managementsystem 5 according to the embodiment. FIG. 26 is a sequence diagramillustrating the process of transmitting captured-image data and audiodata in video calling according to the embodiment.

The communication unit 18 a of the image capturing device 1 a transmitscaptured-image data obtained by capturing a subject or surrounding andaudio data obtained by collecting sounds to the communication unit 38 aof the videoconference terminal 3 a (step S101). Because the imagecapturing device 1 a is a device that is configured to obtain twohemispherical images, from which a spherical panoramic image isgenerated, the captured-image data is configured by data of the twohemispherical images as illustrated in FIG. 3A and FIG. 3B. Thevideoconference terminal 3 a receives the captured-image data at thecommunication unit 38 a.

Next, the data exchange unit 31 a of the videoconference terminal 3 atransmits, to the communication management system 5, the captured-imagedata and the audio data received from the image capturing device 1 a(step S102). Along with the captured-image data and the audio data, animage data ID identifying the captured image data, which is atransmission target, is also transmitted. Thus, the communicationmanagement system 5 receives the captured-image data and the image dataID at the data exchange unit 51.

Next, the data exchange unit 51 of the communication management system 5transmits the captured-image data and the audio data to otherparticipant communication terminal (i.e., smartphone 9, the PC 7, andthe videoconference terminal 3 d) participating in the same videocalling in which the videoconference terminal 3 a is participating(steps S103, S104, S105). At each of these steps, along with thecaptured-image data and the audio data, the image data ID identifyingthe captured-image data, which is a transmission target, is alsotransmitted. Thus, the smartphone 9, the PC 7 and the videoconferenceterminal 3 d receives the captured-image data, the image data ID and theaudio data, at the data exchange unit 91, the data exchange unit 71, andthe data exchange unit 31 d.

Next, referring to FIGS. 27A, 27B and 27C, display examples on thedisplay 917 in the site B are described according to the embodiment.FIG. 27A is an illustration of a screen displayed in the site B, inwhich the screen includes an image based on captured-image datatransmitted from the image capturing device 1 a in the site A via thevideoconference terminal 3 a, and another image based on capturedimage-data transmitted from the image capturing device 1 b in the siteB, without generating a spherical panoramic image and apredetermined-area image. By contrast, FIG. 27B is an illustration of ascreen displayed in the site B, in which the screen includes images thatare displayed after a spherical panoramic image and a predetermined-areaimage are generated based on the captured-image data transmitted fromthe image capturing device 1 a in the site A and the image capturingdevice 1 b in the site B. In the example of FIG. 27A to FIG. 27C, animage of the site A is displayed in a left-side display area (layoutnumber “1”) of the display 917, and an image of the site B (own site) isdisplayed in an upper-right display area (layout number “2”). Further,in a middle-right display area (layout number “3”) of the display 917,an image of the site C is displayed, and an image of the site D isdisplayed in a lower-right display area (layout number “4”). The displayarea having the layout number “1” is a main display area, and thedisplay areas with the layout numbers “2”, “3” and “4” are sub displayareas. The image to be displayed in the main display area and the imageto be displayed in the sub display area can be switched in eachcommunication terminal. In general, an image having a main person in thevideo calling is displayed in the main display area at each site.

When captured-image data transmitted from the image capturing device 1 aand the image capturing device 1 b, each being configured to capture aspherical panoramic image, are displayed as they are, the images of thesite A and the site B are displayed as illustrated in FIG. 27A, i.e.,each image is displayed as a combination of a hemispherical image on thefront side and a hemispherical image on the back side, as respectivelyillustrated in FIG. 3A and FIG. 3B.

On the other hand, when the image and audio processor 93 generates aspherical panoramic image based on each of the captured-image datatransmitted from the image capturing device 1 a and the image capturingdevice 1 b, each of which is configured to obtain two hemisphericalimages from which a spherical panoramic image is generated, and furthergenerates a predetermined-area image, the generated predetermined-areaimage, which is a planar image, is displayed as illustrated in FIG. 27B.Further, in both of FIGS. 27A and 27B, the general image (planar image,in this example) is displayed in the display areas of the site C andsite D, because the image capturing device 8 and the camera 312 built inthe videoconference terminal 3 d, each being an image capturing devicethat obtains a general image, are used in the site C and the site D,respectively.

Furthermore, a user in each site can change a predetermined areacorresponding to the predetermined-area image in the same sphericalpanoramic image. For example, when the user B1 operates using the touchpanel 921, the acceptance unit 92 receives the user operation to shiftthe predetermined-area image, and the display control unit 94 shifts,rotates, reduces, or enlarges the predetermined-area image. Thereby, adefault predetermined-area image in which the user A1 and the user A2are displayed as illustrated in FIG. 27B, is changeable to anotherpredetermined-area image as illustrated in FIG. 27C, for example. Morespecifically, in FIG. 27C, the predetermined-area image is changed fromone including the users A1 and A2 to another one including thewhiteboard 6, in the captured image of the site A as illustrated in FIG.25B.

Sphere icons 191 and 192 illustrated in FIGS. 27B and 27C are examplesof a special image identification icon indicating an image beingdisplayed is a predetermined-area image corresponding to thepredetermined area T in a spherical panoramic image. Although inexamples of FIGS. 27B and 27C, the sphere icons 191 and 192 aredisplayed in an upper right corner, in another example, the sphere icons191 and 192 are displayed at any other suitable position such as in anupper left corner, a lower left corner, a lower right corner. Inaddition, a type of each of the sphere icons 191 and 192 is not limitedto the one illustrated in FIG. 27B and FIG. 27C. Further, in alternativeto or in addition to the sphere icons 191 and 192, a character stringsuch as “Spherical Image”, or a combination of an icon and characterscan be used.

Referring to FIG. 28, an operation performed by the image communicationsystem is described, when a predetermined-area image as illustrated inFIG. 27B is displayed and the predetermined-area image is changed fromthe one illustrated in FIG. 27B to another one illustrated in FIG. 27C.FIG. 28 is a sequence diagram illustrating an operation of sharingpredetermined-area information. In FIG. 28, the videoconference terminal3 a in the site A is an example of a third communication terminal, thevideoconference terminal 3 d in the site D is an example of anothercommunication terminal, and the smartphone 9 in the site B is an exampleof the communication terminal (own terminal).

First, when the user D1, D2 or D3 operates the videoconference terminal3 d in the site D to display the predetermined-area image of the site Aas illustrated in FIG. 27B, the data exchange unit 31 d of thevideoconference terminal 3 d transmits, to the communication managementsystem 5, predetermined-area information indicating thepredetermined-area image currently being displayed (step S111). Thispredetermined-area information includes the IP address of thevideoconference terminal 3 a, which is a sender terminal of thecaptured-image data and the IP address of the videoconference terminal 3d, which is a destination terminal of the captured-image data. In thisexample, the videoconference terminal 3 d is also a sender terminal ofthe predetermined-area information. The communication management system5 receives the predetermined-area information at the data exchange unit51.

The data storage/read unit 59 of the communication management system 5stores, in the predetermined-area management DB 5003, thepredetermined-area information and the IP address of the sender terminaland the IP address of the destination terminal, which are received atstep S111, in association with one another (step S112) The processes insteps S111 and 112 are performed each time the predetermined-area imageis changed in the videoconference terminal 3 d, for example, from theone as illustrated in FIG. 27B to another one as illustrated in FIG.27C.

The data storage/read unit 59 of the communication management system 5reads out, from a plurality of sets of the predetermined-areainformation and the IP address of each of the sender terminal and thedestination terminal stored in the predetermined-area management DB5003, the latest (the most recently stored) set of predetermined-areainformation and the IP address of each of the sender terminal and thedestination terminal, at regular intervals such as every thirty seconds(step S113). Next, the data exchange unit 51 distributes (transmits) thepredetermined-area information and the IP addresses read in step S113,to other communication terminals (the videoconference terminal 3 a, thesmartphone 9, the PC 7) participating in the same video calling in whichthe videoconference terminal 3 d, which is the sender terminal of thepredetermined-area information, is participating (steps S114, S116,S118). As a result, the videoconference terminal 3 a receives thepredetermined-area information at the data exchange unit 31 a. The datastorage/read unit 39 a stores the predetermined-area information and theIP addresses received in step S114 in association with one another inthe predetermined-area management DB 3003 a (step S115) In substantiallythe same manner, the smartphone 9 receives the predetermined-areainformation at the data exchange unit 91. The data storage/read unit 99stores the predetermined-area information and the IP addresses receivedin step S116 in association with one another in the predetermined-areamanagement DB 9003 (step S117). Further, PC 7 receives thepredetermined-area information at the data exchange unit 71. The datastorage/read unit 79 stores, in the predetermined-area management DB7003, the predetermined-area information received in step S118 inassociation with the IP addresses that are also received in step S118(step S119).

Thus, the predetermined-area information indicating thepredetermined-area image changed in the site A is transmitted to each ofthe communication terminals in the other sites B, C and D participatingin the same video calling. As a result, the predetermined-areainformation indicating the predetermined-area image being displayed inthe site A is shared by the other communication terminals in the othersites B, C and D. This operation is performed in substantially the samemanner, when the predetermined-area image being displayed at any one ofthe communication terminals in the sites B, C, and D is changed.Accordingly, the predetermined-area information indicating thepredetermined-area image displayed by the communication terminal in anyone of the sites is shared by the other communication terminals in theother sites which are participating in the same video calling.

Referring to FIG. 29 to FIG. 34, a description is given of using thepredetermined-area information shared by the communication terminals inthe different sites, according to the embodiment. FIG. 29 is a flowchartillustrating steps in an operation of displaying a predetermined-areaimage according to the embodiment. Since the same or the substantiallythe same operation is performed at each communication terminal, anoperation performed by the smartphone 9 in the site B is describedbelow. More specifically, a description is given of an operationperformed by the smartphone 9 in the site B, when the videoconferenceterminal 3 d in the site D displays a predetermined-area image based oncaptured-image data transmitted from the videoconference terminal 3 a inthe site A, and the videoconference terminal 3 d transmitspredetermined-area information indicating the predetermined-area imageto other communication terminals participating in the same videocalling.

First, the data storage/read unit 99 of the smartphone 9 searches theimage type management DB 9001 (FIG. 16) using the image data ID receivedat S103 in the process illustrated in FIG. 26 as a search key, to readout the image type information (source name) associated with the imagedata ID (step S131).

Subsequently, the determination unit 95 determines whether the imagetype information read in step S131 indicates “special image” or not(S132). When the image type information read in step S131 indicates“special image” (S132: YES), the data storage/read unit 99 searches thepredetermined-area management DB 9003 for predetermined-area informationindicating a predetermined-area image being displayed by each of thecommunication terminals in the other sites (step S133). Next, thedetermination unit 95 determines whether the predetermined-areainformation indicating the predetermined-area image being displayed bythe communication terminal in each of the other sites is managed in thepredetermined-area management DB 9003 (step S134). When thepredetermined-area information indicating the predetermined-area imagebeing displayed by each of the communication terminals in the othersites is managed in the predetermined-area management DB 9003 (S134:YES), the calculation unit 97 calculates a position of a predeterminedarea T2 with respect to a predetermined area T1 in a whole image, basedon predetermined-area information (i2) indicating the predetermined-areaimage of the predetermined area T2 displayed by the smartphone 9 (ownterminal) and the predetermined-area information (i1) indicating thepredetermined-area image of the predetermined area T1, which information(i1) is received by the data exchange unit 91 from the communicationterminal in the different site and stored in the predetermined-areamanagement DB 9003 (step S135). The position calculated in step S135indicates, in a strict sense, a position of a point of gaze of thepredetermined area T1 with respect to a point of gaze of thepredetermined area T2. The point of gaze is the center point asdescribed above. In another example, the point of gaze is an upper leftcorner (or a lower left corner, an upper right corner, or a lower rightcorner) of a rectangle of each of the predetermined areas. In stillanother example, the point of gaze is a specific point within each ofthe predetermined areas.

Referring to FIGS. 30A and 30B, a description is given of how the pointof gaze of the predetermined area T1 with respect to the predeterminedarea T2 in the whole image is calculated. FIG. 30A is an illustrationfor explaining definitions of angles of the virtual camera. FIG. 30B isan illustration for explaining how the position of the point of gaze ofone of the other site in the predetermined-area image of the own site iscalculated by parallel projection viewed from above.

As illustrated in FIG. 30A, the calculation unit 97 acquires a movingradius r, a polar angle θ, and an azimuth angle φ from thepredetermined-area information indicating the predetermined-area imagebeing displayed by the display control unit 94 of the own terminal(smartphone 9), and sets the acquired information as CP1 (r0, θ1, φ1).Next, the calculation unit 97 acquires a moving radius r, a polar angleθ, and an azimuth angle φ from the predetermined-area information of oneof the other site read out in the step S133, and set these informationas CP 2 (r0, θ2, φ2).

Considering the predetermined area T2 being displayed by the ownterminal (smartphone 9) and having its center at the point of gaze CP 1,a width w and a height h of the predetermined area T2 are projectedrespectively to w and a length of h cos θ1 in FIG. 30B obtained byparallel projection from the polar direction.

Further, the moving radius of the point of gaze CP 1 is projected to alength of r0 sin θ1, and the moving radius of the point of gaze CP2 isprojected to a length of r0 sin θ2. Accordingly, the point of gaze CP1is positioned at coordinates (r0 sin θ1·r0 cos φ1, r0 sin θ1·r0 sin φ1)and the point of gaze CP2 is positioned at coordinates (r0 sin θ2·r0 cosφ2, r0 sin θ2·r0 cos φ2).

As described above, since the coordinates of the point of gaze CP1 andthe point of gaze CP2 are derived in FIG. 30B, the position of the pointof gaze CP2 on a plane of the predetermined area T2 having the width wand the height h can be derived using general coordinate transformation.

Referring to FIGS. 31A and 31B, a description is given of how thedirection of the predetermined area T1 with respect to the predeterminedarea T2 in the whole image is calculated. FIG. 31A is an illustrationfor explaining definition of angles, according to the embodiment. FIG.31B is an illustration for explaining definitions of angle ranges,according to the embodiment.

As illustrated in FIG. 31A, the calculation unit 97 acquires an azimuthangle φ from the predetermined-area information indicating thepredetermined-area image being displayed by the display control unit 94of the own terminal (smartphone 9), and sets this azimuth angle φ as arotation angle φ1. Further, the calculation unit 97 acquires an azimuthangle φ from the predetermined-area information of the different siteread out in step S133, and sets this azimuth angle φ as a rotation angleφ2. Furthermore, the calculation unit 97 calculates the differencebetween the rotation angle φ2 and the rotation angle φ1, and sets thecalculated difference as a rotation angle φ3.

As illustrated in FIG. 31B, assuming that an angle range with its centeron the rotation angle φ of the own site is α1, and an angle range withits center on an angle obtained by adding 180 degrees to a horizontalangle of the own site is α2, the calculation unit 97 calculates thedirection of the predetermined area T1 with respect to the predeterminedarea T2 in the whole image, which may be referred to as a “positionalrelationship” as follows.

(1) When the rotation angle φ3 is included in the angle range α1, thepositional relationship is determined as “forward direction”.

(2) When φ3 is included in the angle range α2, the positionalrelationship is determined as “backward direction”.

(3) When φ3 is included neither in the angle range α1 nor in the anglerange α2, and is greater than 0 degree and less than 180 degrees, thepositional relationship is determined as “rightward direction”.

(4) When φ3 is included neither in the angle range α1 nor in the anglerange α2, and is equal to or greater than 180 degrees and less than 360degrees, the positional relationship is determined as “leftwarddirection”.

Next, the image and audio processor 93 generates a predetermined-areaimage including a gazing point mark indicating the point of gaze and adisplay direction mark indicating the direction calculated by thecalculation unit 97 (step S136). A display position of the gazing pointmark is obtained directly from the position of the predetermined area T1with respect to the predetermined area T2 in the whole image. A displayposition of the display direction mark is obtained by the determinationprocessing of (1) to (4) described above using the position of thepredetermined area T1 with respect to the predetermined area T2 in thewhole image. At this step, based on the image type informationindicating the “special image”, the image and audio processor 93combines each of the sphere icons 191 and 192 indicating a sphericalpanoramic image with each of the predetermined-area images. Then, asillustrated in FIGS. 32A, 32B and 32C, FIGS. 33A and 33B, and FIG. 34,the display control unit 94 displays the predetermined-area imagegenerated in step S136 (step S137). FIGS. 32A, 32B and 32C are views,each illustrating a display example of the predetermined-area imageincluding display direction marks, which image is displayed in the maindisplay area. FIGS. 33A and 33B are views, each illustrating a displayexample of the predetermined-area image including gazing point marks,which image is displayed in the main display area. FIG. 34 is a viewillustrating a display example of the predetermined-area image includingdisplay direction marks and a gazing point mark, which image isdisplayed in the main display area. Although in fact, as illustrated inFIG. 27, images of all sites where the communication terminals areparticipating in the video call are displayed, in FIGS. 32A, 32B and32C, FIGS. 33A and 33B, and FIG. 34, only the image of the site A isillustrated in order to simplify the drawing.

As illustrated in FIG. 32A, in the predetermined-area image, which is apart of the image of the site A, display direction marks m11, m13, m14are displayed, each indicating a direction of the predetermined-areaimage displayed by each of the communication terminals in the othersites with respect to the predetermined-area image being displayed bythe smartphone 9 in the site B (own site) in the whole image. Displaydirection marks m21, m23, m24 illustrated in FIG. 32B correspond to thedisplay direction marks m11, m13, m14 illustrated in FIG. 32A,respectively. Further, display direction marks m31, m33 and m34illustrated in FIG. 32C also correspond to the display direction marksm11, m13, m14 illustrated in FIG. 32A, respectively. Each displaydirection mark is an example of direction information. The directioninformation can be represented in any other suitable form. In anotherexample, the direction information is indicated by characters such“right”, “left”, “back” and “front” instead of by an arrow.

Further, as illustrated in FIG. 33A, in the predetermined-area imagewhich is a part of the image of the site A, gazing point marks m41 andm42, each indicating the point of gaze of the predetermined-area imagedisplayed in each of the other sites with respect to thepredetermined-area image being displayed in the site B (own site) in thewhole image, are displayed. The gazing point marks may besemi-transparent so as not to hide the predetermined-area image. Gazingpoint marks m51 and m52 illustrated in FIG. 33B correspond to the gazingpoint marks m41 and m42 illustrated in FIG. 33A, respectively.

In FIG. 33A, in order to enable the user B1 or B2 to identify whichsite's point of gaze is indicated by each of the displayed gazing pointmarks, the displayed gazing point mark m41 includes “C”, which is a nameof the site C, and the displayed gazing point mark m42 includes “D”,which is a name of the site D. On the other hand, in FIG. 33B, althoughthe site names are not displayed, patterns of the gazing point marks m51and m52 are different from each other, thereby indicating differentsites. In this case, if a table associating the patterns and the sitenames with each other is prepared, the user in each site can identifythe site based on the pattern of the gazing point mark. For example, thetable is printed on paper. In another example, the table is stored ineach site as electronic data.

In addition, instead of the patterns, colors or line types can be usedto distinguish the gazing point marks. The gazing point mark is anexample of relative position information. In FIG. 34, the gazing pointmark m41 indicating the point of gaze of the other site (site C) whichis within the predetermined-area image, is displayed. Further, in FIG.34, the display direction marks m11 and 14 indicating the direction ofthe predetermined-area image displayed by each of the communicationterminals in the other sites (site A and site D) are displayed, becausethe points of gaze of these sites are not within the predetermined-areaimage.

Referring again to FIG. 29, when the determination unit 95 determinesthat the predetermined-area information indicating thepredetermined-area image displayed by the communication terminal in eachof the other sites is not managed in the predetermined-area managementDB 9003 (S134: NO), the image and audio processor 93 generates apredetermined-area image that does not include the gazing point mark andthe display direction mark (step S138). Then, the operation proceeds tostep S137.

Further, when the determination unit 95 determines that the image typeinformation does not indicate “special image” (S132: NO), that is, whenthe image type information indicates “general image”, the image andaudio processor 93 does not generate a spherical panoramic image fromthe captured-image data received in step S103, and the display controlunit 94 displays a general image (step S139).

As described above, the users B1 and B2 in the site B can recognize therelative positions between the predetermined-area image displayed in theown site and the predetermined-area image displayed at one or more ofthe other sites. This prevents the users B1 and B2 in the site B frombeing unable to keep up with discussion in a meeting, etc.

<<Effects of Embodiment>>

As described above, the communication terminal, such as thevideoconference terminal 3 a, according to the present embodiment,generates a spherical panoramic image and a predetermined-area imagebased on image type information associated with the image data IDtransmitted with image data. This prevents the front-side hemisphericalimage and the back-side hemispherical image from being displayed asillustrated in FIG. 27A.

Further, a user in a given site can recognize which part of a wholeimage of the spherical panoramic image is displayed as thepredetermined-area image in one or more of the other sites. For example,this makes it easier for the user to keep up with discussion in ameeting or the like as compared with a conventional art.

Further, in the operation illustrated in FIG. 28, if the communicationmanagement system 5 transfers predetermined-area information receivedfrom the videoconference terminal 3 d to the other communicationterminals, each time the communication management system 5 receives thepredetermined-area information from the videoconference terminal 3 d,the users B1 and B2 are prevented from concentrating on video callingdue to flickering of the gazing point mark and the display directionmarks illustrated in FIG. 34. To address this matter, as the processesin steps S112 to S114, the communication management system 5 transmits,at regular intervals, a set of the latest (the most recently stored)predetermined-area information and the IP addresses. This allows eachuser to concentrate on video calling.

Second Embodiment

Referring to FIG. 35, a second embodiment is described. FIG. 35 is asequence diagram illustrating another example of an operation of sharingpredetermined-area information described above referring to FIG. 28. InFIG. 35, the videoconference terminal 3 a in the site A is an example ofa communication terminal (own terminal), and the videoconferenceterminal 3 d in the site D is an example of another communicationterminal.

In the first embodiment, as illustrated n FIG. 28, the communicationmanagement system 5 once stores predetermined-area informationtransmitted from any one of the communication terminals (see step S112)and transmits predetermined-area information at regular intervals toeach of the other communication terminals other than the communicationterminal that transmits the predetermined-area information (see stepsS114 to S119). By contrast, in the second embodiment, as illustrated inFIG. 35, not the communication management system 5 but any one of thecommunication terminals (the videoconference terminal 3 a, in theembodiment) as a transmission source of captured-image data once storespredetermined-area information (see step S213), and transmitspredetermined-area information to each of the communication terminalsother than the own terminal (the videoconference terminal 3 a) atregular intervals (see steps S215 to S221). In other words, according tothe present embodiment, a communication terminal as a transmissionsource of captured-image data manages how a predetermined-area imagerepresenting the predetermined area T1 is displayed by anothercommunication terminal based on the captured-image data transmitted fromthe own terminal (the videoconference terminal 3 a, in the embodiment).

The system, hardware and functional configurations of the presentembodiment are same or the substantially the same as those of the firstembodiment. The difference between the present embodiment and the firstembodiment is an operation illustrated in FIG. 28. Therefore, in thefollowing, the operation different from the first embodiment isdescribed referring to FIG. 35. The same reference numerals are given tothe same or corresponding functions or configurations as those of thefirst embodiment, and redundant descriptions thereof are omitted orsimplified appropriately.

First, when the user D1, D2 or D3 operates the videoconference terminal3 d in the site D to display a predetermined-area image of the site A,the data exchange unit 31 d of the videoconference terminal 3 dtransmits, to the communication management system 5, predetermined-areainformation indicating the predetermined-area image currently beingdisplayed (step S211). This predetermined-area information includes theIP address of the videoconference terminal 3 a, which is a senderterminal of the captured-image data, and the IP address of thevideoconference terminal 3 d, which is a destination terminal of thecaptured-image data. In this example, the videoconference terminal 3 dis also a sender terminal of the predetermined-area information. Thecommunication management system 5 receives the predetermined-areainformation at the data exchange unit 51.

Next, the data exchange unit 51 of the communication management system 5transmits the predetermined-area information including the IP addressesreceived in step S211 to the videoconference terminal 3 a, which is asender terminal of the captured-image data (step S212). Thevideoconference terminal 3 a receives the predetermined-area informationat the data exchange unit 31 a.

Next, the data storage/read unit 39 a of the videoconference terminal 3a stores, in the predetermined-area management DB 3003 a, thepredetermined-area information and the IP address of the sender terminaland the IP address of the destination terminal, which are received atstep S212, in association with one another (step S213). The process ofstep S213 is a process of managing how the captured-image datatransmitted from the own terminal (videoconference terminal 3 a, in theembodiment) is displayed in another communication terminal. Theprocesses in steps S211 to S213 are performed each time thepredetermined-area image is changed in the videoconference terminal 3 d.

The data storage/read unit 39 a of the videoconference terminal 3 areads out, from a plurality of sets of the predetermined-areainformation and the IP address of each of the sender terminal and thedestination terminal stored in the predetermined-area management DB 3003a, the latest (the most recently stored) set of predetermined-areainformation and the IP address of each of the sender terminal and thedestination terminal, at regular intervals such as every thirty seconds(step S214). Then, the data exchange unit 31 a transmits thepredetermined-area information including the IP addresses read out instep S214 to the communication management system 5 (step S215). Thecommunication management system 5 receives the predetermined-areainformation at the data exchange unit 51.

Next, the data exchange unit 51 of the communication management system 5transmits (distributes) the predetermined-area information including theIP addresses received in step S215 to each of the communicationterminals (videoconference terminal 3 d, smartphone 9, PC 7) (stepsS216, S218, S220). The videoconference terminal 3 d receives thepredetermined-area information at the data exchange unit 31 d. The datastorage/read unit 39 d stores, in the predetermined-area management DB3003 d, the predetermined-area information received in step S216 inassociation with the IP addresses that are also received in step S216(step S217). In substantially the same manner, the smartphone 9 receivesthe predetermined-area information at the data exchange unit 91. Thedata storage/read unit 99 stores, in the predetermined-area managementDB 9003, the predetermined-area information received in step S218 inassociation with the IP addresses that are also received in step S218(step S219). Further, PC 7 receives the predetermined-area informationat the data exchange unit 71. The data storage/read unit 79 stores, inthe predetermined-area management DB 7003, the predetermined-areainformation received in step S220 in association with the IP addressesthat are also received in step S220 (step S221).

<<Effects of Embodiment>>

As described above, according to the present embodiment, a communicationterminal as a transmission source of captured-image data collectspredetermined-area information indicating how each communicationterminal displays an image based on the captured-image data transmittedfrom the own terminal, and transmits the collected predetermined-areainformation to each communication terminal. Accordingly, in addition tothe effects of the first embodiment, a burden is prevented fromconcentrating on the communication management system 5, in the casewhere a large number of communication terminals is participating in thesame videoconference or the like.

Third Embodiment

Hereinafter, a description is given of a third embodiment.

Although in FIG. 10, the image capturing device 1 a includes onemicrophone 108, in the present embodiment, the image capturing device 1a includes a plurality of directional microphones. By using theplurality of directional microphones by the image capturing device 1 a,audio data collected by each of the directional microphones aretransmitted from the image capturing device 1 a to the videoconferenceterminal 3 a. The calculation unit 37 a of the videoconference terminal3 a calculates a direction of a sound source (microphone angle) based onthe audio data collected by each of the directional microphones. Thecalculated direction is used for identifying a position of a speaker (ofa transmission source of the captured image). The same applies to theimage capturing device 1 b. The image capturing device 1 b including aplurality of directional microphone transmits audio data collected byeach of the directional microphones to the smartphone 9. The calculationunit 97 of the smartphone 9 calculates a direction of a sound source(microphone angle) based on the audio data collected by each of thedirectional microphones. The calculated angle is used to identify aposition of a speaker (of a transmission source of the captured image).

<<Effects of Embodiment>>

According to an aspect of the present disclosure, a user in a given sitecan recognize more accurately which part of a whole image of a sphericalpanoramic image is displayed as a predetermined-area image is displayedin one or more the other sites.

[Supplementary Information on Embodiment]

In the above embodiment, a description is given of an example in whichthe predetermined area T is specified by predetermined-area informationindicating an imaging direction and an angle of view of the virtualcamera IC in a three-dimensional virtual space containing the sphericalimage CE. However, the predetermined-area T can be specified any othersuitable information. For example, in a case where the angle of view iskept constant, the predetermined area T may be specified bypredetermined point information indicating the center point CP or anarbitrary point of four corners of the predetermined area T having arectangular shape in FIG. 7. “Predetermined information” includes thepredetermined-area information and the predetermined information.

In the above-described embodiments, a captured image (whole image) is athree-dimensional spherical panoramic image, as an example of aspherical image. In another example, the captured image is atwo-dimensional panoramic image, as an example of a spherical image.

In addition, in this disclosure, the spherical image does not have to bea full-view spherical image. For example, the spherical image can be awide-angle view image having an angle of about 180 to 360 degrees in thehorizontal direction.

Further, in the above-described embodiments, the communicationmanagement system 5 transfers the predetermined-area informationtransmitted from each communication terminal. In another example, thecommunication terminals can directly exchange the predetermined-areainformation between one another.

Each of the functions of the above-described embodiments may beimplemented by one or more processing circuits or circuitry. Theprocessing circuitry includes a programmed processor, as a processorincludes circuitry. A processing circuit also includes devices such asan application specific integrated circuit (ASIC), a digital signalprocessor (DSP), a field programmable gate array (FPGA), a system on achip (SOC), a graphics processing unit (GPU), and conventional circuitcomponents arranged to perform the recited functions.

The above-described embodiments are illustrative and do not limit thepresent disclosure. Thus, numerous additional modifications andvariations are possible in light of the above teachings. For example,elements and/or features of different illustrative embodiments may becombined with each other and/or substituted for each other within thescope of the present disclosure. For example, some of the elementsdescribed in the above embodiments may be removed.

Any one of the above-described operations may be performed in variousother ways, for example, in an order different from the one describedabove.

What is claimed is:
 1. A communication terminal for displaying apredetermined-area image, which is an image of a part of a whole image,the communication terminal comprising circuitry to: receive firstpredetermined information specifying a first predetermined area, thefirst predetermined information being transmitted from anothercommunication terminal displaying a first predetermined-area image,which is an image of the first predetermined-area in the whole image,calculate a position of the first predetermined area with respect to asecond predetermined area in the whole image, based on the firstpredetermined information received and second predetermined informationspecifying the second predetermined area, the second predetermined areabeing an area of a second predetermined-area image being displayed bythe communication terminal; and control a display to display, based onthe position calculated, the second predetermined-area image includingat least one of relative position information indicating the positioncalculated and direction information indicating a direction of the firstpredetermined area with respect to the second predetermined area.
 2. Thecommunication terminal of claim 1, wherein data of the whole image istransmitted from a third communication terminal, which is different fromthe communication terminal and the another communication terminal. 3.The communication terminal of claim 1, further comprising: a memory tostore image data identification information for identifying data. of thewhole image in association with image type information indicating a typeof the whole image, wherein, in response to receiving particular wholeimage data of a particular whole image and particular image dataidentification information identifying the particular whole image data,which are transmitted from the another communication terminal, thecircuitry is further configured to: generate, based on the particularwhole image, the second predetermined-area image in the whole image as aspherical image, when particular image type information associated withthe received particular image data identification information in thememory indicates a spherical image; include at least one of the relativeposition information and the direction information in the generatedsecond predetermined-area image, based on the calculated position of thefirst predetermined area; and control the display to display the secondpredetermined-area image including at least one of the relative positioninformation and the direction information.
 4. The communication terminalof claim 1, further comprising: a memory to store address information ofa sender communication terminal, which is a transmission source of dataof the whole image, address information of a destination communicationterminal, which is a destination of the data of the whole image, andpredetermined information specifying a predetermined-area imagedisplayed by the communication terminal as the destination communicationterminal, in association with one another, and the circuitry is furtherconfigured to: transmit data of a whole image of an own site where thecommunication terminal itself is located, to be received by the anothercommunication terminal; receive the address information of thecommunication terminal itself as a transmission source of data of awhole image received by the another communication terminal and theaddress information of the another communication terminal, both of theaddress information of the communication terminal itself and the addressinformation of the another communication terminal being transmittedtogether with the first predetermined information from the anothercommunication terminal; store, in the memory, the address information ofthe communication terminal itself, the address information of theanother communication terminal, and the first predetermined information,which are received, in association with one another; and transmit theaddress information of the communication terminal itself, the addressinformation of the another communication terminal, and the firstpredetermined information stored in the memory, to be received by one ormore other communication terminals participating a same videocommunication in which the communication terminal itself isparticipating.
 5. The communication terminal of claim 4, wherein thedata of the whole image is transmitted from the communication terminal.6. The communication terminal of claim 5, wherein the circuitrytransmits, at preset intervals, a latest set of the address informationof the communication terminal itself, the address information of theanother communication terminal, and the first predetermined informationstored in the memory.
 7. The communication terminal of claim 1, whereinthe communication terminal includes one of a videoconference terminal, apersonal computer, a smartphone, a digital television, a smartwatch, anda car navigation device.
 8. The communication terminal of claim 4,wherein the communication terminal includes one of a videoconferenceterminal, a personal computer, a smartphone, a digital television, asmartwatch, and a car navigation device.
 9. An image communicationsystem, comprising: the communication terminal of claim 1: the anothercommunication terminal; and a communication management system thatmanages communication of captured-image data between the communicationterminal and the another communication terminal.
 10. An imagecommunication system, comprising: the communication terminal of claim 4;the another communication terminal; and a communication managementsystem that manages communication of captured-image data between thecommunication terminal and the another communication terminal.
 11. Adisplay control method performed by a communication terminal fordisplaying a predetermined-area image, which is an image of a part of awhole image, the method comprising: receiving first predeterminedinformation specifying a first predetermined area, the firstpredetermined information being transmitted from another communicationterminal displaying a first predetermined-area image, which is an imageof the first predetermined-area in the whole image; calculating aposition of the first predetermined area with respect to a secondpredetermined area in the whole image, based on the first predeterminedinformation received and second predetermined information specifying thesecond predetermined area, the second predetermined area being an areaof a second predetermined-area image being displayed by thecommunication terminal; and displaying, based on the positioncalculated, the second predetermined-area image including at least oneof relative position information indicating the position calculated anddirection information indicating a direction of the first predeterminedarea with respect to the second predetermined area.
 12. A non-transitorycomputer-readable storage medium storing a computer-executable programthat causes a communication terminal for displaying a predetermined-areaimage, which is an image of a part of a whole image, to perform a methodcomprising: receiving first predetermined information specifying a firstpredetermined area, the first predetermined information beingtransmitted from another communication terminal displaying a firstpredetermined-area image, which is an image of the firstpredetermined-area in the whole image; calculating a position of thefirst predetermined area with respect to a second predetermined area inthe whole image, based on the first predetermined information receivedand second predetermined information specifying the second predeterminedarea, the second predetermined area being an area of a secondpredetermined-area image being displayed by the communication terminal;and displaying, based on the position calculated, the secondpredetermined-area image including at least one of relative positioninformation indicating the position calculated and direction informationindicating a direction of the first predetermined area with respect tothe second predetermined area.